Question

gases are so easily compressible where as it is impossible to compress solid or liqid

Answer 1

Gases completely fill the vessel in which they are.
They have high compressibility and so are compressed.

Answer 2

Gases are easily compressible because there is a huge space between the particles of gases but there is almost negligible space between the particles of solids and liquids. So the particles can be compressed upyog when there is a limited space between them .