UPLOAD

Sending files from your computer to another computer through the Internet. For example, sending email is uploading a file to the SMTP server of your ISP. When you have a personal home page, you must upload your HTML files to the Web server that hosts your Web site.

Transferring a file or files from the user's computer to a remote computer.

Transfer of files off a local computer up to a specified remote computer(as opposed to download where files are pulled off a remote machine).

To send or transmit a file from one computer to another via modem (compare "download").

If downloading is receiving a file from another computer, uploading is the exact opposite. It is sending a file from your computer to another one. Pretty straight forward. It is possible to both upload and download at the same time, but it may cause slower transfer speeds if you have a low bandwidth connection. Because most files are located on huge ftp servers, people generally do a lot more downloading than uploading.