HTML, hypertext markup language.
If you don't know what HTML is then it's a code you use on computer to make websites. HTML is not case sensitive so you can take a load off your mind. At the beginning of any code you have to insert this '<html>' and at the end of the code you put '</html>'. Both of those are called tags. So then lets get started!
Bold, Underlined and Italic
If in HTML coding you want to make something bold you just put a '<b>' at the beginning of the bold area and you put a '</b>' at the end of the bold area. Simple. For Underlined writing you type '<u>' and for the end of the underlined area you type '</u>'. Now guess what Italic is is HTML?