How do you use an ATTINY? what can it do?

How do you use an ATTINY? what can it do? how do you program it, and what are the pins? Please give me any and all info on ATTINY. :-\

You have the internet at your fingertips and the route you chose is to expect people to feed ALL the information to you?
Even if someone did, I'm guessing most of it would go right over your head.

How about you start with explaining what you want to do, and then maybe someone can tell you if an ATTiny chip is suitable?

how do you program it

You use a programmer, which you can make from an Arduino. Plenty of circuits arround. I used what are called zif sockets, Zero Insersion Force, so that their is no need to keep plugging the chip in and out of a socket.

Check this link for all the info.

You can make a chess clock out of one. What do you want to do?

This video is a start:- How-To: Shrinkify Your Arduino Projects - YouTube

This is what I made with mine. A drum that echos back what you tap. It was designed for an autistic kid who liked the feel of the buzz when he hugged it. The Neopixel LEDs change colour for each tap it plays back so you can use it to teach counting as well.

I have a project I'm working on that uses only 1 input and 1 output. I don't exactly need a Mega for that.