Network Protocols
A Network Protocol is a standard method for transmitting data through a network. There are many different specialized protocols to accommodate the many kinds of data that might be transmitted. The most common protocol is HyperText Transport Protocol (HTTP). HTTP (HyperText Transport Protocol): An Internet protocol for transferring "hypertext" files. It typically requires the host to use an HTTP server program, and the viewer to use a HTTP client program.
FTP (File Transfer Protocol): An Internet standard for transferring files over the Internet. FTP programs and utilities are used to upload and download webpages, graphics, and other files from your hard drive to a remote server which allows FTP access.
SMTP (Simple Mail Transfer Protocol): A protocol used to transfer email between or among servers. POP (Post Office Protocol): A protocol used to transfer email to individual computers. IMAP (Internet Message Access Protocol): A protocol includes operations for creating, deleting, and renaming mailboxes; checking for new messages; permanently removing messages; searching; and selective fetching of message attributes, texts, and portions thereof. It does not specify a means of posting mail; this function is handled by a mail transfer protocol such as SMTP. DNS (Domain Name Server): DNS server helps dictate the IP addresses associated with domain names and vice versa. Every browser request for a gloabl website requires a communication with a DNS server for directions. Many more network protocols exist and more are sure to evolve with time. In every case, PHP can initiate a connection via the desired network protocol and transparently perform updates, uploads/downloads, informational scans, and so on. There are too many protocols and potentially beneficial PHP functions to include here.