How does redshift differ from blueshift?
This is seen in the Spectrum of the Object.
An Object in Space is said to be Blue shifted when it is moving towards us, i.e. the absorption wavelengths in the spectrum of that object are shifted towards the Blue wavelengths in the Electromagnetic spectrum i.e. towards the left.
Light from an Object in Space is said to be Red Shifted when it is moving away from us, i.e the absorption peaks are shifted towards the Red wavelength in the electromagnetic spectrum i.e towards the right.