Hello,
Freezing will render the selected tracks to audio with all of the processing on the track included in that render.
Example:
1. Make sure that the loop markers in the sequencer encompass the entire song, start to finish.
2. Open the freeze dialog.
3. Select “In Place”.
4. Select the tracks to be frozen (usually the ones that use up a lot of CPU).
5. Click OK.
6. Once it is done those tracks are now rendered in the background and do not use up your CPU resources.