If you have been on Twitch for a while, you've probably seen SOME form of role play in one capacity of another. It comes in many forms, and at its most basic is people with similar interests joining together in a game to play out a role.
Role play has existed in our lives further back than we can probably even prove. Bedrooms, brothels, acting, spies... its about pretending to be someone you aren't. One of the more well known and popular forms of role play is Dungeons and Dragons (D&D) which had books that gave rules, guidelines, and help toward creating fun games to join together in around a table.
The internet also helped creative a new 'genre' of role play so to speak, called MUDs. What they became were text-based role play, done in chat rooms or forums. Essentially its the same as that D&D game around a table, but its people around the world joined in a single chat room instead for example. These are still popular today, even if its a bit of a dying art. Find the right corners of the net, and you'll still come across text role players. Its one of my own personal favorite styles too.
I have done role play since my pre-teen years. It began on a computer unit called WebTV, where I joined in on local chat rooms and watched what they were doing. When I felt comfortable enough, I joined in and got a feel for it. I continued to do so off and on for the next 20 years (and still do.) I have also role played in one of the growing trends in recent years, MMO's.
Typically in an MMO you are questing, battling other people, and leveling your character for better gear and skills. Some people took it upon themselves though to create entire servers devoted to role play. You get all the same content, but the players on that server enforce strict "in character only" chat. So when you interact with another player, you'll be doing so as the character you portray instead of as you the player. People build grand stories and adventures around this.
The main appeal of role play is story telling. Either you tell a story, or you participate in a story someone else is telling. You get to take part in a story live and ongoing, almost like a Choose Your Own Adventure book. The people in charge of the story (called a DM or GM; Dungeon or Game Master) will provide what you need to participate, and then you play. Its a lot more fun than I think I can properly tell you in this blog alone. If you love to read though, or write, or act... I suggest you dabble a bit in any role play you discover to see if its something you could enjoy. Don't judge it off one try though, as so many things can go wrong in a single session of role play. Try it a few times, and if you still notice you are not enjoying yourself... maybe its not for you. You can still enjoy watching/reading it though!
Some places I can recommend you to look for role play is the following: Twitch (GTA role play and other MMO's, D&D, VRChat), Gaia Online (forum/avatar based), Facebook groups, chat clients (nearly all of them will have a role play section), and Google Search. Be mindful some role play falls into the erotic category, so double check what it is before you join in on it.