Other forms: uploaded; uploading; uploads
When you send any kind of data from your computer to the internet, you upload it. Want to change your social media profile picture? Just upload a new photo — maybe that one of you and your cat dressed in matching sweaters!
Any time you share photos online, submit an assignment to the school website, or even send an email, you upload data. Typically this means transferring electronic information from an individual computer to a larger network or server. To download is the exact opposite — when you download something, you transfer it from a server to your computer. Both words date from about 1980.