This is really simple, unless you don’t know about it.
If you send someone the address of a web page (the URL) in an email message you want them to be able to click on it so they can go right to it.
Most of us get in the habit of doing a copy and paste so we don’t make any mistakes. After all, web addresses can be really long. The problem with those long addresses is that once they go in an email they may break over a line. When that happens you have a problem, because the web browser on your friend’s computer won’t be able to read it properly any more. The web browser isn’t smart enough to go down to the next line in the email message looking for the rest of the web address.
The solution is to put the URL within the greater than < and lesser than > symbols. The web browser will know that anything contained within those two symbols < > is to be considered a single item. I always put email addresses within the symbols as well when I am sending them to someone in an email. Saves lots of hassle.