Let's say I want to link to another post on the forum. I've started replying to your topic ... so now I can use the search to find the topic I want to link to.
and then select some relevant quote from that post and then click on the "QUOTE" button
and it will be added to my reply to you.
This is great because it adds a link to that other Topic along with some context
If I wanted to link to ANOTHER website I can go to that site in another browser, click on the URL in the address bar
and then you can copy that (either ctrl-c, or right click and select the copy option), then paste that (ctrl-v) on a standalone line and it will embed that link in your reply - like this page from @MSboros
I just added the URL "http://foodmed.net/2017/01/23/daa-bed-big-food-low-fat-paleo-lchf/" on a line by itself and it gets embedded.
If you wanted to insert a link in your page with a description you can use the "chain link" icon to add the url and the text you want to appear in the link
and it will look like this
The Dietitians Ass. of Australia
I'm going to move your topic to the HOWTO section. Thanks for giving me a chance to explain this subject so that others can also stumble upon it