Grandstream phone is a VoIP/IP telephone designed for internet-based calling in offices, businesses, hotels, schools, and call centers. These phones connect through a network instead of traditional phone lines and support features like HD voice, SIP accounts, conferencing, call transfer, voicemail, Bluetooth, Wi-Fi, and PoE (Power over Ethernet). Grandstream offers desk phones, cordless Wi-Fi phones, and video phones for different business needs.