Perferal:everything attached to computer is perferal.
We have two kinds of perferals:output perferal,input perferals.
Output perferal:the things the computer gives out for us like speaker and printer and etc.
Input perferal:the things we do and it goes to computer like keyboard and mouse and etc.
In 1945 the first computer was invented.
A computer is a device you can put and take out information from it.