Capacitor
A capacitor is a electronic device which stores electrical charge in it is an wonderfull device used in electronics

the above figure is an capacitor one terminal is long and one terminal is short long is anode and short is cathode
there are different types of capacitor
1.Electrolytic Capacitor(>1micro Farad)
2.Non Electrolyitic Capactiors(<1 micro Farad)
The above figure shows the electrolytic capacitor
Non Electrolytic capacitors are divided into two types
1.Polyster
2.Disc

Polyster

Disc

How to calculate the values of Capacitor 

The Electrolyte Capacitor has a value written on it but for the Non Electrolyte capacitor it is differnent 

103pF=10,000*10^-9

1*10^-5

0.1micro Farad

Diode

A diode is an electronic device which conducts only in one direction i:e uni directional 

Diode

It is an semi conductor device it is represented as 1N4007

1=one semi conductor junction

N=N type semi conductor

4007=denotes the registration number

one of the major type diode is LIGHT EMITTING DIODE 

Transistor

A tranistor is a device which transfers current from low resistance device to high resistance device 

there are two types of transistor one is pnp and npn

Transistor is mainly used for switching and amplification purposes

BC547 represents the npn series

BC557 represents the pnp series 

Transistor