Upload files/PDF's solution

Hi folks, this might be a dumb question but what type of technology or solution would you call having the ability to upload a document to a website securely?

At our company we want to look into and possibly have the ability directly off our website to securely provide end users to upload a form from their PC to our website and have it empty into a mailbox, folder, etc... What would I Google to get hits and learn more. Thanks so much and sorry for the novice question.