Sorserv (IRC Services) is an IRC addon, that is, it is an extension to IRC and not part of the original IRC protocol. The addon provides registration services for user nicknames and channels on IRC, and it provides additional tools to help administrators see and take action against abuses of their server and enforce their policies.
The addon is implemented as a pseudo-server. That is, under normal operation, services exists as a server node in the IRC network and provides its services under the pseudonym of "fake" user nodes on the network who are used when any request needs to be made of services and who are used to return the results of the request to the user who made it.
So services is not truly an IRC server or part of IRC itself, nor are the "services users" really users, but to the network they appear as such, and the basic IRC commands for interacting with services are the same as those for interacting with an ordinary IRC Robot (or user).
Requests to services are sent over IRC's private message facility, and services' answer to a request is returned in the form of a private notice.
Although the services package allows an administrator of services to name the services units however they like, the typical names of the services provided by the sorserv addon are:
OperServ
Handles most administrative requests, and it is an interface usable only by global operators of the IRC system.
NickServ
Has the domain of requests (including administrative ones) that relate to the registration, ownership, and control of use of nicknames on the IRC system.
ChanServ
Has the domain of requests (including administrative ones) that relate to the registration, ownership, and control of use of channels on IRC.
InfoServ
Has the domain of requests (including administrative ones) that relate to the automated distribution of "news articles" by services on IRC.
GameServ
Handles "dice roll" requests, for use by roleplayers