What are the advantages of using different types of transistors?

[Voltz]

I've recently learnt about the science behind a transistor and its uses but now I've stumbled upon something new, there isn't one type of transistor... there are loads! But I wanted to know the advantage of using a:
n-MOSFET
p-MOSFET
PNP Transistor
NPN Transistor
J-FET Transistor

What's the point of having these different types, do they do different jobs? Are some specialized? Or do they all have the same function/efficiency and its up to people to pick? Thanks Guys

 

[Boncuk]

not an easy answer if the application isn't known.

An NPN-transistor is controlled by a positive base voltage, a PNP by a negative one compared with the emitter voltage.

N- and P-channel MosFet transistors behave similar with less voltage drop (hence lower losses) than bipolar transistors.

Boncuk

 

[Hero999]

FETs have a high impedance gate which means they don't load the driver circuit much.

Enhancement MOSFETs are used to switch high currents.

Depletion MOSFETs and JFETS are used to amplify small signals.

FETs are voltage to current amplfiers

BJTs are current to current amplfiers.

BJTs have a higher gain than MOSFETs but they have a lower input impedance.

P type devices are used to switch the positive rail and N type devices are used to switch the negative rail.

EDIT:
If you study all the devices you've listed, including schematics which use them, you should be able to answer the question yourself.

 

[ljcox]

P & N types are complementry, hence CMOS.

Each type of transistor has its advantages & disadvantages.

You use which ever type is the most appropriate to a particular application.

One type that has been missed is the IGBT (Insulated Gate Bipolar Transistor).

It is a combination of a MOSFET & a Bipolar and combines the advantages of both.

These are the high imput impedance of a MOSFET which reduces the drive issues and the low saturation voltage of a Bipolar.