A web server is a software that stores website files for example Html, CSS and Javascript and other doctypes and renders it on the web page.

There are many web servers and Apache is one of the best web servers which is been around since 1995 and can handle a large amount of traffic Apache 2.0 can now run in a hybrid multiprocess, multithreaded mode. This improves scalability for many, but not all configurations.

Html stands for the (Hyper Text Markup Language) and when it comes to HTML, Have you ever thought of why there's index.html, not anything else we know that's it's standard but there's one more that we can use alternative and that is default.html and we can also use (index.htm) where the L is missing but it would still work and we are become so used to for using the index.html we don't use now default.html but both works's the same.

Block & Inline: Block is when the content uses a certain space but setting it at the block it covers the entire space line irrespective of the content size whereas In Inline the content covers the space equal to the size of the content.

h1/h2 Tags: We use the h1/h2 tag for organising the structure of our content and the same goes with the other tags which <p> tag for the paragraph and several others example <small> and so on.

There are many tags in the Html but recently I've learned some new tags which are these follows:
<blockquote>:- This is used when we need to specify the section that is quoted from the other source
<pre>:- This tag is quite useful while writing a poem in HTML
<sub> & <sup>:- This tag is used when we need to quote the formula.
<audio> & <video>:- In the audio tag it is very important to add controls autoplay muted inside the tag. So that while loading the page the audio will not get played at the first. It should be muted.

Extentiontions: Talking about the extension we all use the Live server by Ritwik dey in VScode but for people who don't use it much the second one and which is I think better than the Liver server is Live server Preview where we can see the live changes side by side and easier than changing the window alternatively after every change made.

Accessibility: When it comes to accessibility the best or we could say the most valuable web pages are the ones which can be accessible by people with disabilities. The web page contains visual contents like images and video links since the blind person can't see but these individuals might see access the computer's output using synthesized text-to-speech technology known as a "screen reader.
A web page with the Button, Menu, and Tab should be accessible for those with physical disabilities who are unable to operate a mouse will be unable to access these controls. All controls should be operable with a keyboard as well.