cURL is a completely ubiquitous tool used for making network requests over every protocol you have heard of, including: HTTP, HTTPS, IMAP, DICT, FTP, Kerberos, LDAP, MQTT, POP3, FTPS, Gopher, RTSP, RTMP, SCP, SMTP, SMB, SFTP, Telnet, TFTP, LDAPS, proxies, and more.