That device can be booted in both RouterOS and in SwitchOS (you can decide which one to use).
RouterOS is (essentially) command line (but there is Winbox and the webfig http interface, both are GUI “overlays”).
SwitchOS is GUI only (and overall more similar on how you would configure other common managed switches).
The device name begins with CRS that in Mikrotik parlance means Cloud Router Switch, in practice CRS devices are mainly switch devices with some (slow, only good for remote management or other minor traffic) router capabilities.
RouterOs is “more powerful” and very flexible, but it has a steep learning path, particularly for configuring a switch.
SwitchOS allows far less freedom, but it was designed specifically to manage switches.
Most people on the forum are familiar with RouterOS because they use Mikrotik routers and/or AP’s, so for them it is more “natural” to use RouterOS also on switches (the ones that support it) and SwitchOs is then considered less convenient, but for a switch it is just fine.
In this recent thread you can have an idea on how SwitchOS looks and what it can do (in regards of VLANs):
http://forum.mikrotik.com/t/vlans-port-isolation-in-switch-os-how-does-it-all-fit/181080/14
If that is the only Mikrotik device in your network, it would IMHO make sense to try configuring it in SwitchOS, and only if you cannot have it doing the whatever you want it to do think of changing the booting OS to RouterOS: