Almost every VPN service provider you encounter will make some claim about logs. Records can be kept for a variety of reasons. An unlogged service is seen as a critical selling element. Fast and safe VPNs are popular among users who want to improve their privacy and anonymity. They wouldn't want to go from one company following them to another. Although it would be ideal if all VPN apps maintained no logs, the reality is that many do. These could include logs of websites viewed (rare) or usage logs such as time spent connected to the fast and safe VPN and bandwidth consumed.