What is ping on RuneScape?

Answer 1

Answering your question as fully as possible, Ping measures how well your connection is with the host, the higher the badder since this will produce lag in your game, the lower the better since the host is close by providing a smoother gameplay.

Full detail

Having a low ping is always desirable because lower latency provides smoother gameplay by allowing faster updates of game data.

Ping is often conflated with lag. One may "lag out" due to unacceptably high ping. Servers will often disconnect a client if the ping is too high and it poses a detriment to others' gameplay. Similarly, client software will often mandate disconnection if the ping is too high. A high ping is not the result of lag; rather, a high ping causes lag.