Lag

Lag, from "lag behind", is a slang term for slow Internet speeds, sometimes due to a server problem, but more frequently due to the connection between client and server.

Lag can be used as follows, "Gee, anybody else noticing that Wikipedia is lagging periodically, or is it just me?"

In computer science, proposals to alleviate lag are part of Quality of Service.

Lagger

A lagger (occasionally, High Ping Bastard) is someone who, in today's age of broadband Internet, uses a 56 kbps modem to connect to the Internet, then joins a multiplayer online game (usually a first-person shooter) and who has a very high ping time. This causes the game to lag.

Low Ping Bastards

Low Ping Bastard or LPB is a phrase that originated during the time when Quake was a highly popular multiplayer online first-person shooter. The term came into common usage when broadband Internet connections first came into the reach of home users and were competing with people limited to a 56 kbps or slower modem connection. This term was so widely used because of the havoc wreaked upon the other users of these servers by the low ping bastards due to their overwhelming advantage in reaction time afforded by their connection