What's the difference between Y aminobutyric acid and Y coumaric acid?

The difference between γ -aminobutyric acid and γ -coumaric acid lies in:

1, γ-aminobutyric acid is a natural amino acid which is not composed of protein, and it is widely found in animals and plants.

2.Y- hydroxybutyric acid, abbreviated as GHB, has functional group differences with Y- aminobutyric acid in structure, and the name is only a word difference, but they are very different.