Why uploading and downloading a file is required ? Explain with example.

When we need a file which is located on the server, we have to download the file that means a transmission of the file from the server to the local computer. For example, when we make a reservation for a seat of the train, we download the train ticket from the server to our computer and get a printout of the ticket.

Similarly, if we want to share some content (file, picture, video etc.) and we want it to be visible online, we have to upload that content on the Internet i.e., a transmission of the file from our computer to the server. For example, uploading a picture on our social media account.