V2Ray is the sub-section of Project V that's responsible for network protocols and communication. It draws some parallels to proxy software Shadowsocks, but is intended more of a platform, with any developers able to use the provided modules to develop new proxy software.
V2Ray and its VMess protocol were designed to improve on the performance and features of Shadowsocks and aid in detection prevention. When deploying V2Ray, you can dynamically change port, access advanced routing features, use obfuscation techniques, chain proxies, and more. Though this makes V2Ray more complicated than single proxy protocols like Shadowsocks, it means it can be used for more niche configurations and scenarios.