The hcf full form is Highest Common factor.
H = Highest
C = Common
F = Factor
The highest common factor or greatest common divisor is the maximum number that divides each of the given numbers.
Examples:
Consider the set of numbers 2, 4, 2.
2 = 2
4 = 2*2
2 =2
HCF = 2
Consider another set of numbers 4, 4, 10.
4 = 2*2
4 = 2*2
10 = 2*5
HCF =2