Why I have need to learn HTML?

If you have a website or planning for creating in the future. So you should
learn at least some basic html (HyperText Mark-up Language). Even if someone else is developing your website there are some basics things you should know. If the person who are developing your website is not available and your need to modify your website, in this situation what will your do?

I always believe that if you have a business, website or whatever you are doing, you should have some knowledge about how it works.

With the knowledge of HTML you will be able to designing a web page exactly as you want it, and formatting the text as needed.
If you are planning to make money from internet marketing and you make an offer on your email, you will have to provide a clickable link. In either case, you will have to know about some html tag to make a hyperlink.