2N2222A by Texas Instruments is a small signal NPN bipolar junction transistor (BJT) with a max collector-emitter voltage of 40V and a max collector current of 0.8A. It is commonly used for switching applications due to its fast turn on/off times (35ns/285ns) and high transition frequency (300MHz).
LM2931Z-5.0RPG by Onsemi is a Fixed Positive Single Output LDO Regulator with 5V Nominal Output Voltage, 0.1A Max Output Current, and 6V Min Input Voltage. It operates in temperatures ranging from -40 to 125 °C and is ideal for applications requiring stable voltage regulation in electronic circuits.