Server

A server is a device that provides functionality for other programs or devices, called "clients." This architecture is called the client–server model. A single server is designed to be accessed by multiple processes or devices. In MMORPGs such as Ragnarok Online and Ragnarok Online II, players have the option to choose from multiple servers to play the game. The term "server" can refer to a different version of the game, such as the Asia servers or the North America servers, or the internal servers in one version of the game. This can often be confusing as different versions of RO and RO2 occasionally use the same internal server names for their respective versions.

Ragnarok Online
In RO, players have the option to choose from PVM or PVP servers. Players can only learn which servers are PVM or PVP through their publisher as the server selection window only shows population counts for each server. Players can also see the population of the server they're currently in with the /who command. Some versions of RO have chosen to hide the character count from the server selection window and disable the /who command to dispel accusations of population decline.

Ragnarok Online II
In RO2, players only have the option to play on PVM servers as PVP options exist in the game. Unlike RO, RO2's server selection window does not display character counts. Instead it shows population health bars for each server's channel set, with green indicating low populations while red indicates high populations. RO2 servers are designed to host more characters due to the channel system, which allows more players to play on the same server.

Patches
Ragnarok Online Ragnarok Online II
 * Patch (2017 Aug. 01)
 * The display in the number of characters in the server selection UI will be changed.
 * The content displayed depends on the server status. (Comfortable / Normal / Congested / Saturated)
 * The /who command is now disabled.