You can share files and directories from the Qnap TS-210 to any other computer because the Qnap uses Linux or Unix with the usual array of sharing software available in Linux.
Windows uses a sharing system based on SMB and Linux has a matching sharing system named Samba. Linux and Unix can also use NFS and other options.
The Qnap device will be online 24 hours a day every day and your network should be up all the time. Every time you switch on your computer, the Qnap should be available instantly. All you need is automated connection to the shares you need on the Qnap.
The Qnap device was named Q210nas during installation. The device appears as Q210nas(SAMBA) in the Places, Network display. All my Linux based computers use Ubuntu Linux and have Samba installed by default. Sharing using Samba is so easy that I do not see a reason to share using anything else.
I also have a Windows computer and having the windows compatibility using the same sharing system is a bonus.
When you first access a share in Samba, you select the share and enter your user name, password, and the workgroup name. You can tell the Samba access form to remember the password forever. If everything works together, you login to the share just once then connect automatically forever.
Finding a SMB (Samba) share in Windows is complicated by Windows looking first in a Windows workgroup. To use workgroups, you have to make all your computers join the same workgroup and joining a workgroup is a pain in Linux.
If you want to access a Samba share outside of a workgroup, you have to manually specify a network path.