File Transfer Protocol (FTP) is a standard network protocol used to transfer files between hosts over the Internet. Applications will normally use it as a means of uploading or downloading files to/from different hosts. FTP was not designed as a secure protocol, and as a result has several security vulnerabilities, the biggest being unencrypted traffic, which allows eavesdropping. Since security is an important aspect of almost all applications, it is not desirable to use FTP in its standard form.
SFTP is secure FTP, allowing all FTP communication to be secure over Secure Shell (SSH). In this form, all communication and data is encrypted, preventing preying eyes from intercepting communication and eavesdropping.