When I first started working with WordPress, the versions I was using did not come with a built in mechanism to upload new themes and plugins. It does have that capacity now. Before the only option was to upload Plugins and Themes by FTP. As a technical newbie, although I knew what FTP was I did not know HOW to FTP something. Finally someone said, “Oh just use Filezilla” ( there are lots of other FTP programs, for example, Fetch is one for Macs. Bingo, problem solved. Although you can auto install them now, What I do is keep a whole treasure trove of my favorite plugins and themes on my computer and then when I do a new WordPress install I FTP them into the new install all in one fell swoop. Here is how to do that.