vz.+year is military designation.
Like your M16 or M4
Sa / TK /UK /LK /SHKH / Pi etc.. is "what it is" e.g. Sa - samopal - submachinegun , T - heavy, L - light, U -universal, K - machinegun. Pi - pistole, SHKH selfpropeled wheeled howitzer and so on.
ZB - Zbrojovka Brno , CZ - Česká...