Does <i> define important text?

Answer 1

I'll recommend you to go through your HTML course once
https://www.sololearn.com/learn/HTML/1026/

Answer 2

Italic text

Answer 3

To make text italic <i> tag is used.
You can also use <em> tag

Answer 4

i makes the text only italic.
em also makes the text italic, but it also indicates that the text is important.