First of all, when you make a comment, it becomes obsolete in the code itself (it’s not read) but it’s still visible to you and anyone else viewing the code. This exercise asks you to turn your background-color rule into a comment so that you can make it obsolete for now, without straight up deleting it.
body {
background-color: blue;
text-align: center;
}
This code gives the body element a blue background, and centers all text in it. Now, I’ll turn the text-align rule into a comment:
body {
background-color: blue;
/* text-align: center; */
}
Because I turned it into a comment, the text-align rule is now obsolete. It’s still visible, but now it’s not actually executed, so the body element will have a blue background, but its text will not be centered.