Computer are general-purpose devices programmed to carry out a set of arithmetic or logical operations automatically. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem.
In general, a computer consists of at least one processing element, typically a central processing unit (CPU), and some form of memory. The processing element carries out the operations, while the sequencing and control unit changes the order of operations in response to stored information.
Peripheral devices allow information to be retrieved from an external source (the internet, another computer, etc.), and store and retrieve whatever operations the computer(s) is/are working on.
Many people use computers of different sorts on their daily lives and work. If you're looking for something specific--a desktop model, a laptop, a tablet, or even one of the new wearables--take a look at these videos and see if you can't find it here!