There is also Carrier Grade NAT, which basically means that you share an IP with other customers, so if you try to access your network from the outside, you will only end up at your ISP's router, where the network is divided up for a group of customers.
No, I specifically meant dynamic, because most ISPs only give static IPv4 for business plans, and a dynamic IP is fine if you use a dynamic DNS service (the Fritzbox has one).
There is also Carrier Grade NAT, which basically means that you share an IP with other customers, so if you try to access your network from the outside, you will only end up at your ISP's router, where the network is divided up for a group of customers.