Linkrot is internet slang for the condition where hypertext links lead nowhere because Web sites have removed Web pages or reorganized them.
To prevent linkrot, web sites can add redirects, which automatically take users to the correct URL, or, they can provide the new and correct url on the old page. The only issue with redirects is that they essentially void any ranking gained through key words that you previously embedded into html code with the old URL.
I had to learn this the hard way. The ranking for the webpage sharply deceased practically overnight when I added a redirect to the new home page, which I had been link building for months. I had to do this because I changed the URL of the website. Since then, I basically had to begin the SEO process for that webpage from scratch.
My new website can be seen
here. It is basically an essay writing service