FileZilla is a free and open-source, cross-platform FTP application, consisting of FileZilla Client and FileZilla Server. Clients are available for Windows, Linux, and macOS. Both server and client support FTP and FTPS (FTP over SSL/TLS), while the client can in addition connect to SFTP servers. FileZilla's source code is hosted on SourceForge.
FTP stands for File Transfer Protocol, and operate very differently from HTTP.