What is uploading?
Usually, from long time Internet users used it for download files but if someone wants to do it, then another have to sent it. On the systematic, in Internet language it is called upload. It is the opposite process to download. Usually, the connection link has two parts: one for download and second for upload. This link can be symmetric (download and upload bandwidths are the same) or asymmetric (upload bandwidth is lower than download bandwidth). It means that sending to the network is slower than downloading. Usually, users are interested in their bandwidth during download process. A few people know that upload is also important. Before your computer will download a web page, it has to send download request to the server so. Also, there are some applications (e.g. P2P) that effectively "suck" upload transfer. This may cause a delay in sending queries and hence the charge content of external websites.
Lately, upload became a good solution to earn money on the network. Why? A lot of companies pay for uploading files to some servers. A pay depends on a lot of factors. Usually, from a download country (country with a higher PKP have higher rates). When someone downloads our files, then we earn money - simple!
How can we upload and where?In the network it is a lot of services, which upload files. It is called hosting sites like Imageshack, Megaupload etc. Usually, user has allotted amount of space on the site. When she/he wants it more, then she/he can buy it. On the Internet we can sent files differently: via mail, via instant messaging protocol, to server FTP. In the case of e-mail the outgoing mail server calls SMTP is responsible for uploading. If we want to send files to another user by IM, then we have to use some application to sending. The same situation is with FTP. We need FTP client. If we upload file, we need client and receiving files server.