Download/upload

Can someone explain to me and perhaps give an example of the difference between a download and an upload. The terminology of the upload is relatively new to me. Thanks!

Basically, downloading is transferring data to your computer whereas uploading is transferring data from your computer.

An example of downloading would be saving a picture from the internet to your hard drive.
An example of uploading would be attaching a picture on your hard drive to your post.

They are relative terms, depends on where you're standing. Are you throwing the ball or catching it?

Throwing the ball - upload
catching the ball - download