The Compaq 56K (V90) Mini PCI is a 56K dial-up modem card typically used in laptops or desktop PCs with a Mini PCI slot. This modem allows the computer to connect to the internet over a telephone line via dial-up, offering speeds up to 56 kilobits per second (Kbps). Although dial-up connections have become largely obsolete due to broadband and mobile internet, some older systems or specific use cases may still rely on this type of connection.