Inkjets generally tend to use water based inks, which allow for a greater colour gamut (range of colours) and more vivid printing and finer detail due the way they operate.
Essentially inkjets have a series of nozzles (there are between 300 and 600 which are even tinier than a human hair!) arranged on the print head through which precisely timed droplets are fired.
If you want to get REALLY techincal, inkjets which utelise the Piezoelectrical method to eject ink, patented by Epson, allow for even greater degree of fine tuning as variable sized droplets of ink can be created allowing for more detailed prints! pretty clever stuff really...
