I am what people call a 'multiboxer', which means I'm playing several characters at the same time. I do this using 8 different World of Warcraft accounts attached to the same Battle.net account, all of which are registered in my name. This means that all 8 characters also shares the mounts, pets, toys, transmog and achievements.
Using the top menu, you'll find some information about what multiboxing is, and the reason why I am doing it. There are also screenshots of Blizzard Game Master posts stating that it is FULLY ALLOWED, and that it is not any form of botting.