A screwdriver is a tool, manual or powered, for screwing and unscrewing. The offset screwdriver has a handle set at right angles to the small blade,. OK, let' s get serious about tools.
You may be thinking of ' jumping in' and purchasing a lot of pricey tools from such as Snap- on. Even if you are planning to be a professional, I do NOT recommend that.
For details, please see the respective articles.