Socket Type Constants : socket_create « Network « PHP

Socket Type Constants

SOCK_STREAM        A sequenced and reliable bidirectional connection-based stream. Most common in use. 
SOCK_DGRAM         An unreliable, connectionless socket that transmits data of a fixed length. Very good for streaming of data where reliability is not a concern.
SOCK_SEQPACKET     Similar to stream sockets, except data is transmitted and received in fixed-length packets.
SOCK_RAW           A raw socket connection, useful for performing ICMP (Internet Control Message Protocol) operations such as traces, pings, and so on.
SOCK_RDM           A reliable but unsequenced socket similar to that of SOCK_DGRAM.

Related examples in the same category

1.Creating a Simple Socket-Based Server
2.Domain Constants for Socket Connections
3.Retrieving a Website Using Sockets