Nextiva offers cloud-based communication solutions for small to medium-sized businesses and enterprises, with a focus on VoIP phone services that allow calls over the internet. Their NextOS platform integrates various tools such as video conferencing, team messaging, and CRM software to streamline business communications. Unlike competitors, Nextiva's subscription-based model allows for customization and scalability, while also providing SIP trunking services for modernizing existing phone systems. The company's goal is to enhance business operations and customer interactions through efficient communication tools.