This indicates whether a gadget can accommodate two SIM cards. Active and inactive dual-SIM phones are the two main varieties. While Dual-SIM Active (DSA) allows both cards to receive calls simultaneously, Dual-SIM Standby (DSS) requires the user to choose which of the two SIMs can initiate and receive calls. The latter feature typically necessitates a separate transceiver for the supplementary SIM card, which uses up more battery power. The Dual SIM Dual Standby (DSDS) technology found in more current models allows them to have two active SIMs with just one transceiver.