ds-7616ni-e2/8p/a

Hello, I see model DS-7616NI-E2/8P/A has 16 channels and 8 PoE ports: DS-7616NI-E2/16P-Hangzhou Hikvision Digital Technology Co. Ltd. How do you make use of the 16 channels when you have 8 network ports ? All others PoE models I could see have the same number of channels and PoE ports ? Thx.