Bypassed: Go to IP > Hotspot > IP Bindings > and add a new item. One of the "type" options is bypassed, which simply means they don't have to login. From the wiki, "
bypassed - performs the translation, but excludes client from login to the HotSpot" (
http://wiki.mikrotik.com/wiki/Manual:IP ... P_Bindings)
Authorized: If someone connects to the hotspot, they show up in the Hosts tab but are not yet authorized. Once they log in, they show up in the Active tab and are now authorized.
DHCP: If your computer is configured for DHCP, when you connect to the hotspot, you will be given an IP address from the hotspot's DHCP pool. On the other hand, if you configure your computer with a static IP address and connect to the hotspot, you will not be given an IP address from the DHCP pool but will use the static one you have configured.
Static / Dynamic: I am not entirely sure about these two in context. They could be referring to static and dynamic IP addresses (
http://wiki.mikrotik.com/wiki/Manual:IP/Address#Summary), but possibly something else. Maybe someone else can comment?
HTH