Using if-elif-else, we can execute different blocks of code conditionally based on some user-defined logic.

The general syntax is as follows:

if <conditional check 1 is True>: # the if conditional is mandatory
	<code block 1> # executed only when check 1 evaluates to True
elif <conditional check 2 is True>: # the elif conditional is optional
	<code block 2> # executed only when check 1 is False and check 2 is True.
else:
	<code block 3> # executed only when check 1 & check 2 are False.

Note that only the if statement is mandatory. elif and else statements are conditional.

Example:

score = 90

if score > 90:
    print("Grade A")
elif score > 80 and score <=90:
    print("Grade B")
else:
    print("Grade C")

# Output
# Grade B