BSP - British Standard Parallel. Common British hydraulic connection, primarily used as a hose coupling (swivel), not found much outside the UK (JIC or SAE used elsewhere) It seals (metal to metal) on a chamfer on the Id of the fitting. The male threaded fitting has a female chamfer seal (opposite of JIC). We use a lot of them as hose connections on HP nitrogen hoses and hydrotest hoses. Straight (parallel) threads
NPT - Non Parallel threads. VERY common threaded connection, pipe, fittings, gauges. Has a taper thread to effect the seal. Needs to be used with somes form of sealant (PTFE etc.)
