Are all transistors the same?

Hint: Transistors are of various kinds depending on the materials used, functions, size, composition, concentration etc. We will read more about transistors in the upcoming paragraphs.

Complete step by step solution:
Based on the structure there are mainly two categories, they are bipolar junction transistors (BJTs) and field effect transistors (FETs).BJTs amplify a small current coming into their base to a larger current flowing through their collector and emitter whereas the FETs consist of three terminals namely, source, gate, and drain. These are controlled by a voltage from their gate to source, which results in the flow of current through their channel from drain to source. Hence, BJT is a current controlled device and FET is a voltage-controlled device.

NPN and PNP transistors are the families of BJT, where N stands for material with a greater number of electrons (negative) and P material has a greater number of holes (shortage of electrons, positive).

FETs is divided into two types as follows,
1. JFET (Junction Field Effect Transistor) and
2. MOSFET (Metal Oxide Semiconductor Field Effect Transistor)

The Junction FET transistor is a type of field-effect transistor used to control a switch electrically. Electric energy travels through an active channel between the sources and the drain terminals.MOSFET is a field-effect transistor with the MOS structure and has three terminals with gate (G), drain (D) and source (S).

Hence, we can say that all transistors are not the same.

Note:MOSFETs have been classified into two types based on their operation modes:
1. Depletion
2. Enhancement
In the enhancement mode, gate voltage induces the channel and in depletion mode, the MOSFET operates owing to the existing channel.