An if statement within another if statement is known as nested if statement. Similarly, any decision logic can be written within an else statement also.
Have a look at the below example of nested if:
Example
num1=10
num2=20
num3=30
if(num1>num2):
if(num1>num3):
print("num1 is greater")
else:
print("num3 is greater")
elif(num2>num3):
print("num2 is greater")
else:
print("num3 is greater")
Output
num3 is greater
in this above example, one if statement is inside of another if block. It’s good example of nested if statement.