I just need a seemingly simple question answered. Can you explain to me the difference between both of these links. Why are some links put on some websites with just plain hypertext on a page that has it enabled? And the other links that you have to copy and paste HTML code in your "page source", usually when trading links with another website? I know it seems silly but i dont know the answer.
If you're talking about user generated content - such as comments - then the website is running software that looks for the signs of a URL and adds the required HTML mark-up to make it the text clickable. Not every site does that, and if they don't your just get a non-clickable text URL.