The easiest way to tell the two apart is calicos have white, and torties don't. Calicos are typically orange, black, and white.Tortoiseshells are also known for their attitude, hence the term used widely among owners as "tortitude". They are often feisty and sassy, and fiercely independent whereas calicos can be affectionate. The terms calico and tortoiseshell refer to the color pattern of a cat (almost exclusively female btw), and they are not breeds.
Although most people know that the vast majority of calico cats are female, they don’t always know that calico refers to a color pattern, not a breed of cat.