How does this code convert the decimal to binary? [duplicate]

Question

Having difficulty to understand this code. Can somebody explain to me in a simple way.

# decimal to binary
def convert(num):
    if num == 0:
         return 0
    else:  
#explain this part          
     --> return (num % 2 + 10 * convert(num // 2)) <--
        
decimal = int(input())
print(convert(decimal))