Biometric templates may be stored in the memory of readers, limiting the number of users by the reader memory size (there are reader models that have been manufactured with a storage capacity of up to 50,000 templates). User templates may also be stored in the memory of the smart card, thereby removing all limits to the number of system users (finger-only identification is not possible with this technology), or a central server PC can act as the template host. For systems where a central server is employed, known as "server-based verification", readers first read the biometric data of the user and then forward it to the main computer for processing. Server-based systems support a large number of users but are dependent on the reliability of the central server, as well as communication lines.