If (serial.available()) conditional statement I am very new to Arduino and I have a question I would like to clarify on Serial.Available()

According to Arduino documentation, Available() returns the number of bytes that are stored in the buffer, ready to be read. Why then, both If function below works, when there are data in the buffer? For Scenario A, it appears to me that there is no conditional statement, how then, would the IF function evaluates to TRUE?

Scenario A: IF(Serial.Available())

compare with

Scenario B: IF(Serial.Available()>0)

Thanks in advance!
In C, 0 is false and anything else is true. So if Serial.available() returns 0 it is considered false. If it returns 7, 23, 44, etc it is considered true.