Convert serial.read() to usable int

AWOL:
Are the numbers binary, or ASCII decimal?

ASCII, I am actually receiving data from another arduino.

On the other arduino, I only use:

Serial.println(data);

data is in int form which can be either positive or negative numbers.

I am not sure if I am sending the format incorrectly or not but what I send from Arduino A to Arduino B, the received values are matched with the transmitted values.
But I am not able to use the value on Arduino B...