Memcache::connect() establishes a connection to the memcached server. The connection, which was opened using Memcache::connect() will be automatically closed at the end of script execution. Also you can close it with Memcache::close(). Also you can use memcache_connect() function.
host
       Point to the host where memcached is listening for connections. This parameter
       may also specify other transports like unix:///path/to/memcached.sock
       to use UNIX domain sockets, in this case port must also
       be set to 0.
      
portPoint to the port where memcached is listening for connections. Set this parameter to 0 when using UNIX domain sockets.
timeoutValue in seconds which will be used for connecting to the daemon. Think twice before changing the default value of 1 second - you can lose all the advantages of caching if your connection is too slow.