Need for SFTP
SFTP (secured shell FTP) was invented as an improvement over the FTP (File transfer protocol). The file transfer protocol functioned with a disability that the data being transmitted through it could easily be decoded by unintended recipients. Unlike FTP where the files which were being transferred are just shared with moderate encryption to which the key (password /permission) floats in the open channel leaving the system completely exposed and vulnerable, in SFTP the algorithms in place also scramble and encrypt the passwords and the keys to secure the file transfer session. Only the user who knows the password can open the file after using the key to initiate the decryption process.
SFTP is basically coded as a program so that it can run on multiple platforms and its installation goes on smoothly in all the major operating systems. It even uses a different protocol than the FTP, hence the SFTP is for namesake related to the FTP but they really don’t have the same architecture overlay. This provides marked improvements over other attempts at creating a secured file transference mechanism which had FTP as its base. Thus the architecture could possibly not fail where FTP had gone wrong. Hence the difference in architecture prevents a connection from the FTP server into the SFTP program. Though FTPs can be used to communicate in a special tunnel channel within the SSH architecture the fTP cannot do the same without the SFTP. Hence using SFTP is the best and safest way to transfer files and data in a network.