A mobile proxy works the same as other connections (data center, residential, commercial, enterprise) except it uses a 5G (also known as LTE) cellular modem connected with a cellular carrier. There are numerous cellular carriers around the world. The most common ones in the USA are AT&T, Verizon, and T-Mobile. Each cellular carrier has millions of IP addresses available. This means the chances of you getting the same IP multiple times is very rare.
It is the gateway connection between your internet connected device and websites you’re visiting. It’s known as “intermediary” because of that separation. All devices get a unique IP address when connected to the internet and by using a proxy you hide your real IP address from the outside world. The way to find out if you are using a proxy is by checking your IP address.
In short, mobile proxies are much better to use due to the fact that the IP’s are the same ones everyday users get. You don’t have to worry about bans on whole subnet’s of residential/datacenter IP’s. Instagram, Facebook, Snapchat, Google Ads view the IP’s from these proxies very high. For the most part this results in much longer use of accounts.
More info regarding proxy servers: https://en.wikipedia.org/wiki/Proxy_server