Irr-1:some standard structure, but not enough. The galactic bulge is not located in the center, but still have discs and spirals similar to other galaxies.have lots of gas and young stars

Irr-2: no standard movement, and has a chaotic type structure (no longer resembles any regular structures)

Dwarf: form in shapes differently than other irregular galaxies, some are just small spiral galaxies that have been changed by another galaxy.