Oscilloscope AC and DC range

1 What is the difference between the AC and DC ranges of an oscilloscope?

When using Multisim software for circuit simulation, the oscilloscope has two gears: AC and DC.

For the same signal, sometimes the waveforms of the two gears are the same, but sometimes the waveforms of the two gears are different.

Guess: Is it that the AC position is used for AC signals and the DC position is used for DC signals?

Question: When you don’t know whether the signal is an AC signal or a DC signal, which waveform should you believe?

2 Answers from netizens

The DC mode measures the real signal

The AC mode adds a high-pass filter after the real signal