Truth Table

 Truth Value: 

It is the property of a statement to be either true or false.
example:

if statement: "It is Raining", is true, then its negation will be false ( It is Not Raining.)

A Truth Table Contains the Truth Values.

Assertion & Negation:

An input exists in 2 forms Assertion & Negation. If "NOT" is applied to an input than we call it as in its "Negation form", while input without "NOT" is in "Assertion form". For example:  
                 A   : input is in assertion form
                 A'  : input is in Negation form

Truth Table:
It is a table that shows all the possible set of truth values which a boolean function can have.

It determines all the possible combinations of values and results of logical statements.

example:

For a boolean function F(A,B,C) = A'.B + A.B.C'

Truth Table is:

A	B	C	C’	A’	A’.B	A.B. C’	A’.B + A.B. C’
0	0	0	1	1	0	0	0
0	0	1	0	1	0	0	0
0	1	0	1	1	1	0	1
0	1	1	0	1	1	0	1
1	0	0	1	0	0	0	0
1	0	1	0	0	0	0	0
1	1	0	1	0	0	1	1
1	1	1	0	0	0	0	1

Tautology:

If all the values of a column in a truth table are "1" then that column is said to be tautology.

example: 

In the below truth table Col. 4 (A+A') is a tautology.

A	B	A’	A+A’
0	0	1	1
0	1	1	1
1	0	0	1
1	1	0	1

Contradiction:

If all the values of a column in a truth table are "0" then that column is said to be contradiction.

example: 

In the below truth table Col. 4 (A.A') is a contradiction.

A	B	A’	A.A’
0	0	1	0
0	1	1	0
1	0	0	0
1	1	0	0

Contingency:

If the values of a column in a truth table contains both "0" and "1" then that column is said to have contingency.

example: 

In the below truth table Col. 3 (A.B) is a contingency.

A	B	A.B
0	0	0
0	1	0
1	0	0
1	1	1