<div class="section">

Question

If any know this meaning and use then please tell me

Answer 1

https://www.sololearn.com/discuss/1520044
https://www.sololearn.com/discuss/446121
https://www.sololearn.com/discuss/816832

Answer 2

In css, we can define class as so:
.section {
color: blue;
}
This defines a class "section". We can then assign this class to an element in the HTML, and the styles will be applied to the element.

Answer 3

Please use relevant tags, what are you doing writing 'help me' in tags? you know your question is related to HTML and CSS, so tag either one or both. Either way such tags are better/clearer contextually.
(Edit)
Tags updated by moderators team