The first time Kali Linux VB download is 3.75GB of its size.

I have not install any other external tools in my kali machine. I was just giving the apt update as a regular. Now my Disk Space has been 16GB.

Now, I have downloaded the new VB.
Total updates are just inside 4GB, but it is not the only append for the stand-alone machine to be updated.

1. Why this happens?
2. How to prevent this?