Android 6 seems to show only three* different mobile network states in the status bar:
- E: EDGE (2G)
- 3G: anything from UMTS to HSPA+
- 4G: LTE
While you’re on 3G, you can go to Settings / About phone / Status / SIM status for details.
(* Well, GPRS probably also still exists, but I haven’t seen that in a long time.)