Well-written meta tags help make page rank higher in search results.
To add the description of the program that you need to embed in your website is the generator tag. You can add this generator tag anywhere where you want to not only the index/home page.
Description tag is used to describe the whole page in one or two line description.
Both the tags are helpful to index a page over the search engines.
Specifies an "app name" so that the website can be used like a web-app — this name appears underneath the app icon on mobile devices when the user selects the "Add to Home Screen" function in their web browser.
Here in this cheatsheet you should have almost everything you need to start defining meta tags in your HTML documents.
So put the relevant keyword is important for the web page creator.
Because keyword meta tag is a source to any web page.
Almost all the major search engines talk about description tag and use it also.
You have a direct input on the way to show your website content to the user without visited to the page.