how to test transistor in digital tester, meaning and types

"sorry about 1 mistake, at 1:55 A1941 is PNP not NPN(my mistake) sorry

what is transistor, meaning, and types of transistor, and how to test it in digital multimeter

how to test transistor
what is transistor
kinds of transistor
types of transistor
bipolar junction transistor
mosfet transistors

how to test transistor,what is transistor,transistor in digital,kinds of transistor,types of transistors,bipolar junction transistors,mosfet transistors,