Mass airflow sensor
Mass-airflow codes mean the air-meter signal is out of range or does not match the throttle and rpm.
P0102 is a low input and P0101 is a range or performance fault. A dirty meter, a torn intake boot, or an unmetered leak changes the fuel the ECU commands.
Inspect the boot and the meter before replacing it. The DTC page lists that order.
A trouble code marks a condition to test. It does not by itself prove which part to replace.