FROM SCRATCH

What is the Meaning of the Idiom
FROM SCRATCH?

from the very beginning

This is often used with the verb start.

1. I always used to use a packaged mix when I baked, but on Saturday my grandmother taught me how to make a cake and cookies from scratch.

2. I followed the wrong instructions for my assignment. Now I have to start the whole paper from scratch!

3. He lost everything in a fire when he was 30 years old, and he had to start over from scratch.

4. There were a lot of errors in the program. We decided it would be easier to start from scratch