Data Meta tags are practically used for on-page structuring of your site's elements, which enables optimized web pages for better indexing by search engines, they are located in the HEAD tag region of a web page and are crticial factors for SEO.

The use of correct meta tags to define a character set, page description, keywords, author of the document, and viewport settings among other meta sets like schema metadata and social meta tags (Which is a meta representation of your typical meta tags, but for social media sites eg Facebook, Linkedin, and Twitter).

Recommended Read: 13 Meta Tags For SEO keyword Ranking

Heading Tags are very important in your content optimization for on-page SEO, they are more than references tags, they offer the importance of a headline in succinct to the body that will be the content of the context (Headline). We have up to six tags under the heading tags from H1 to H6 and they are used to relate importance from very important to the least important. The way you use the headline tags is also important in SEO and is classified as a critical factor, there is an amount of H1 tags that are recommended to be on your web page and their placement also matters.

Title optimization is part of Content Optimization where the lenght of your title words are counted, a preferrable character count of 50 to 60 is acceptable and this includes spacing, alphabetic and numeric characters. It is a bad idea to include some irrelvant characters eg using  or and when you can simply use the pipe character "|" or "&" to reduce the amount of pixel required to display all your title correctly without truncating, you can only add special characters when you do not exceed the required length and this characters represents your brand. There is also the matter of stop words like its, a, and, or, etc to mention a few, it is advise to keep them at a minimal as they eat up space and have zero value to search queries, these set of words are ignored by search engines results. But as a blog or content writer You might find them useful to pass information or complete Title message, hence the reduce usage of these words are significant, due to limited Title space.

The Html Structure are the standard markup language for creating Web pages, while a semantic html structure are elements with a meaning, Examples of non-semantic elements: div and span - Tells nothing about its content. Examples of semantic elements: form, table, and article - Clearly defines its content, so an SEO Html Semantic structure are elements that are similar to the functions of headline tags, they emphasize, bold, and makes it easy for search engine to pick up functioning keywords from your web page content, to simply put, they highlight the important keywords. These syntax importance do vary as well like the heading tags, with the emphasis or highlight tags being more important eg b, i, mark, cite, dfn, em, strong, ul (ol, il) than other semantic tags with lesser SEO prefrence like article, aside, details, fig caption, figure, footer, header, main, mark, nav, section, summary, time etc, these are used to define parts of a webpage.

Google wants its users to have a faster loading site that does not take longer than 3 seconds. There are a lot of factors that affect the loading speed of a web page, from the size of the page to the loading structure of each page element and rendering. There are several methods to improve your web page speed, from server-side to minifying and caching from the browser side.
One of the most popular means of increasing server size-speed is to use gzip compression, which is the automated method of reducing the size of files like images, CSS, HTML, text-based files, js, etc from the server-side in order to increase the loading time of a webpage by reducing the size.

Recommended Read: Different Caching Techniques in php

The page speed of your website is not the same as server speed, because server speed tends to optimize the size of your page while page speed amplifies the time it takes your page to render on different viewport devices, page speed is more of user experience oriented, from responsiveness to resources loading time. If you consider fixing all issues that are recommended on the page speed testing platform, you will find out that it helps reduce bounce rates and can increase click-through rates of your Search Engine Ranking.

Recommended Read: Web Page Speed Optimization (Case Study)

Broken links can be a nuissance with your website user experience not to mention it's SEO authenticity, this is why broken links are regarded as a major factor in SEO, and having a steady check for broken links can be a daunting task especially for dynamic websites like cms platforms. If you run a news website or a curating platform you will understand the need to always check for broken links, even sometimes a normal webpage can give off the 404 error page due to miscongiguration from server or htaccess file, broken links can come from outbound or inbound links, and resolving them as quickly as possible can help retain your seo values for your website.
Apart from the broken link result being displayed on our SEO Analysis tool, we do have a stand alone Broken link validator tool whose job is to run series of validation checks on your given URL and present succinct results, the features varies per package subscribe to.

Keyword difficulty index (KEI) or score is a way of measuring the effectivness of your webpage URL to rank for a specific keyword on search engines, this measurement is designated as easy, medium and hard...with each defining the required metrics expected to possibly rank your keyword on the top ten search engine results.
The KEI takes into account the demand and supply for a keyword phrase and also the authority of current ranking pages on search engine along side their links, and content quality of these websites among other SEO factors in comparation to your webpage URL.

The DoFollow and NoFollow tags are ways you improve your internal and external link structure on your website, by simply using the NoFollow in your links to instruct search engine spider not to crawl the link. Mostly dofollow are normally used for external link building, having too many of dofollow links pointing to your website is not recommended as it sends a negative signal to Google that your website is not link worthy. A fair balance of dofollow and nofollow links are a powerful combination to balance the potency and having your linkbuilding look natural, the best combination number of links on a single page should not exceed hundred.

On a lighter note, a DoFollow link require no tags to be placed in their URLs, some dofollows are used naturally on home pages as anchor text found on the navigation section of your website, about us etc search engines can deduce howmany links you have deep structurally from your home page. So it is highly important to let the searchengines know which of your pages on your website are important. And lastly dofollow links always pass juice from link building executed on a page that has good high authority.

The Position of Keywords matters in SEO as it is mostly recommended that you place your most prominent keywords within your first paragraph sentences in your description, your body content and also your "Above the fold" H1 tags headlines.

Take a cue from the Google image above, it shows a good example of ranking keywords with refrence to keyword matching, but with the keywords being placed as the first word in the sentence located in the title tag.

Page Readability Score refers to how your content are being structured are they easy to understand and what lebel of intellegence is required to assimilate your website content, that's Readability score.

We use the Flesch reading ease score, a recognized method for ascertaining the readability of a text. The average sentence length as well as the average number of syllables per word are determined, with both then used to calculate the Flesch score based on the formula: 206.835 - 1.015 * x - 84.6 * y, where x is the average sentence length and y is the number of syllables per word.
The Flesch reading ease score indicates how readable a portion of text is, ranging from 0 (very difficult to read) to 100 (very easy to read). Depending on your text readbility a numeric score will be assigned to your text analysis tagged with a suitable refrence description (readbility level required to understand your text).
The readability score shows which groups of people your text is best suited for. If your target group is primarily academics, an article with a lower readability score will be more appropriate. On the other hand, should your target audience be the general public, that same article would be too difficult for the majority of them to appreciate.

The Keyword density of a web site page is measure by counting the occurrance of a set of keywords on a page and then divide that number of keyword occurance by the total numbe of words found on the page. If you are raning for a keyword on search engine you then need to note the keyword densiity of certain keywords, as it helps to provide you some sense of direction with your keyword content, whether it is off key or not. Hence, you can now set the right keyword to aim for your web page content.

Image optimization is in two parts, one you need to specify the height and width of your image, which is a basic rule but most webmaster do forget this, along side the use of ALT tags to add description of the image. The second part of image optimization is the use of compressing files to reduce the size of that image without losing too much of it's pixel quality, this is done either manually

via image editor tools or via the server side by using mod_deflate and Gzip compress, or better still you utilize a combination of both.

Your users are not only found on laptops or desktops, infact the mobile online users quite as too many digits to over the desktop users, so, when it comes to mobile responsiveness we need to look at how a webpage display correctly with out stretching it's images out of focus or a roken css display of web elements. Your web page should be viewable on all standard view ports and have a good user experience when navigating through the web site. We measure your web site properties in terms of font, button elements, and display view ports to determine if a website is better designed for mobile viewers.

The use of sitemaps and robots.txt files are a major SEO ranking factor. With out the use of sitemaps it becomes difficulty for search engines to priotize your URLs, and there is also a greater chance that irrelevant URLs on your website will probably be ranking for your brand name, eg your policy pages ranking as number one for your brand name instead of your home page.
Now this is one of the reason why you are require to create a sitemap of your entire website URL structure for easy indexing and spidering of important pages of your websites. It is ludacris as some tend to think that not having a sitemap affects the way your link structure are being read, and since the first thing a search engine spider looks for is the robots.txt to know which directories on your site it is barred from indexing, it is quite neccessary to add the sitemap in there as well. A robots.txt defines and restrict the folders or path on your server you want to denie a search engine from accessing, ultimatley having both files are great, but th use of robots.txt is simply for a faster indexing instructions, with out it, you can still rank if you have a well update sitemap.

Recommended Read: 13 Meta Tags For SEO keyword Ranking

Just as the sitemap is relevant to SEO, the same with the number of index pages you have on search engines, you may wonder why does this matter?. The number of index pages you have on search engines tells you how much traffic you could actually earn from possible ranking keywords if they are well optimized for keyword variances pertinent to the page contents. For instance, you have a website that is well-indexed on Google and you have 500 pages indexed, with over 490 being dynamic pages, you can figure if you rank for a single keyword on each, this equates to 500 possible traffic reach in a month for that website. Furthermore, the more index pages you have for your niche market or business will only send a strong signal about your authority on the subject. Your domain can't be saying one thing and your web content is on another...you need to understand if you are a News website then you need to have a focus keyword and not be a jack of all trades.

Domain and URL optimization are basically the way you use your focus keywords in your domain and URL structure, you can take a look at the image for a better understanding. Branded domainsmay have issues with placing their focus keywords in their domain name, but this can be rectify via subdomain names (I will prefer a use of URL keywords rather than a subdomain), with this you can still optimize, but the idea of using a subdomain with your keywords is not advisable as you tend to be contesting against domain authority for each page rather than passing domain juice from example.com to example.com/keyword you will have to contend with building another domain authority for keyword.domain.com as this is seen as another domain entity.

You should consider not using underscores "_" but rather hypens "-" in your domain structure to link words also bad spelling words are not good for optimization, with a domain length not surpassing 8 words (even though search engines do not lay so much empahsises on this, it has be observed that shorter domain with URLs (keywords) do rank higher than their longer counterpart). Also consider your keyword position and URL structure, it is best to organize your urls under categories, either domain.com/car/car-paint or domain.com/date/car-paint, this two examples are unique and one is best suited for an ecommerce and the other is for a blog, adding date to your blog URL makes it stand out for psot that are fresh, search engines place a lot of prefrence for fresh contents, if you have a high quality content that is fresh I can tell you it will rank easily for broad keywords or keyword matches on search engines.

A URL or domain with the HTTPS prefix do have a better chance of improving keyword ranking compared to non-HTTPS websites. HTTPS are security protocols assigend certificates that are electronically signed to a website domain name, which provides security cookies to web browsers to identify the domain name and to tag it has a secured website for visit.

It gradually became a web standard for all prominent website to handle their protocol request via the HTTPS and thus enhance their ranking positionning as well, as newer browser versions do provide warning signs prior visiting a website without HTTPS, which can cause a lot of abandon visit and hence affect organic ranking of such websites position on search engines. Although HTTPS is not a must or requirement for ranking, but it can surely be a boost for your keyword ranking if your website domain name do carries the HTTPS prefix, as lots of SEO webmasters can attest to this fact, that after adding the HTTPS prefix they saw an improvement in their SERP for their respective keywords.

The Domain Authority (DA) is a ranking score given to a website domain name that predicts how likely an occurrence a website will rank on the search engine. This allows you to measure your SEO efficacy from a score of 1 to 100, with a higher score reflecting a greater probability of ranking on search engine ranking pages, the domain authority is a ranking index that was developed by MOZ as an SEO factor.

While the page authority (PA) was developed to replace the Google Page Rank factor that was discontinued by Google, similar to the DA, it tends to predict how well a page will rank on the SERP with its ranking ranging from 1 to 100 as well, with a higher score reflecting a greater probability of ranking on search engines ranking pages, the page authority is a ranking index that was developed by MOZ as an SEO factor.

The Outbound/Inbound links simply referrs to a website structural links which involve both internal and external links pointing to it, eg your home page may have more than 20 inbound links and 5 outbound links all pointing to the same home page, hence this makes the page a high priority page for search engine indexing, simply make sure your outbound links pointing outside are to other website pages that are of high relevancy to your page as well.

Inbound links are used mostly by bloggers or content creators as well to point to indepth pages or old post, inother to get them re-indexed, also the, inbound links can also be classified as links from other websites and they carry weight if they are from authoritative domain and page. Do not over optimize your page with too many outbound and inbound links as any type of link for a webpage should not exceed 100, which is now used as a rule of thumb of link building for keyword SERP.