I don't understand why those two are parallel and one is a series?
Hi Agp2196, and can be recognized as in parallel since they have both ends connected by wires. The bottom ends are connected by a wire, and the top ends are also connected by a wire. This means current at the bottom, coming from the positive end of the battery, has a choice of or , and when you see current being given this choice, you know the resistors are in parallel. Resistor labelled is in series since there are no other options but to go through in order to continue through the circuit.
Hope that helps,