What is an SSL Certificate?What is it?
An SSL Certificate in layman's terms is a vouching system. In other words, you are who you say you are because a large company has verified it.
If I had a company, say like Dak Networks Company, how would you know that the web site you are on is actually the company web site? There's no way of actually knowing. Unless, of course, someone you trust told you that it really was the company web site. Then you would feel secure that you were on the right web site.
This in essence is what an SSL Certificate is. You pay a company. They do a little research to verify who you are. They hand you a certificate. Easier said than done.
Why do you need it?
You need an SSL Certificate to create an SSL connection or to have the HTTPS for you web site.
More importantly, you have to install it correctly for the web site not to complain. If it isn't installed correctly, people get weird messages when they visit your site like "there's a problem with this web site." So unless you want to field phone calls all day long and repeatedly say, "Just click continue" which drives you absolutely insane, you better make sure the SSL Certificate is installed correctly (sounds like I have experience with this?).
I have an SSL Certificate... Now What?
You have to install the SSL Certificate on your server. This is the issue.