Migration assistant stopped halfway, why my storage is occupied (probably by the transferred files)? How can I get rid of it?

Recently I have bought a Macbook Air M1 2020 and transferring my old files from windows into my new Macbook using Migration Assistant. Due to its sheer size, the transfer took a tremendous amount of time.

Before the transfer, my Mac got a plenty of space. From its 256 GB, around 200 GB were still free.

I expected the final size transferred into my mac was around 68 GB since that was the total of my files.

However, during the middle of the transfer, my wifi stopped working and the migration was cancelled.

When I checked at my disk space after the cancellation of the transfer, it showed a new occupied space at around 77 GB classified under "Other". (Picture below) I assumed that this new space was the temporary files created by the migration assistant during the process of transfer, which was failed.

I have tried to restart my Mac several times. However, the effort resulted in no prevail. The space was still there.

In the end, I decided to move my files using an external hard disk. Though I had to spend another money for this transfer process, I succeeded in doing so.

My question is

1. Where I can found this "Other" files?
2. How to get rid of these "Other' files and free up my space?

Thank you. Any helpful answers are welcome.