I want to connect both router via ethernet and Nas, but my computer only have one ethernet port, is it possible to connect the Nas to the router and router to pc?
NAS is a network storage device that connects to the router. After that, you can connect to your NAS from your computer or mobile devices via Ethernet or WiFi.
If you wanted to get a dedicated 1Gbit (or 10Gbit) connection to your computer, then you can also connect directly to your computer via additional LAN (if there is a second LAN, otherwise need to disconnect from the router).
If you get Thunderbolt NAS, you can connect to a computer via Thunderbolt or USB and at the same time give access to other network devices via the LAN.
If you get a Qnap NAS you can also use additional LAN ports on the NAS as a virtual switch. This way, if you have only a single LAN connection on your desk, you can connect other devices as you would on a docking station.
I hope this helps.