postgress processes

shaifali@sa:~$
shaifali@sa:~$ ps auxw |grep -i postgres
postgres  4393  0.0  0.4 251916 16168 ?        S    04:08   0:00 /usr/lib/postgresql/9.3/bin/postgres -D /var/lib/postgresql/9.3/main -c config_file=/etc/postgresql/9.3/main/postgresql.conf
postgres  4395  0.0  0.0 251916  1868 ?        Ss   04:08   0:00 postgres: checkpointer process
postgres  4396  0.0  0.0 251916  2668 ?        Ss   04:08   0:00 postgres: writer process
postgres  4397  0.0  0.0 251916  1652 ?        Ss   04:08   0:00 postgres: wal writer process
postgres  4398  0.0  0.0 252768  3008 ?        Ss   04:08   0:00 postgres: autovacuum launcher process
postgres  4399  0.0  0.0 107736  1816 ?        Ss   04:08   0:00 postgres: stats collector process
shaifali  4841  0.0  0.0  15940   936 pts/0    S+   04:29   0:00 grep --color=auto -i postgres