There are three main features that are used to compare different KVM switches. "Users" refers to the maximum number of users that can simultaneously access and control a single KVM switch (or multiple KVM switches, if they are connected together). Models that accommodate multiple users allow a single administrator to determine the level of access and control provided to each user. "Computer Ports" refers to the maximum number of computers (or servers) that can directly connect to a single KVM switch. The more ports that a KVM has, the more computers that can be connected. "Expansion Capability" refers to the maximum number of computers (or servers) that can be connected to multiple KVM switches which are connected together.