Grounded Theory is a research tool which enables you to seek out and conceptualise the latent social patterns and structures of your area of interest through the process of constant comparison. (A bit like being the x-ray machine of the social world? Though just take the quick idea from that metaphor as it doesn't bear too much examination!) Initially you will use an inductive approach to generate substantive codes from your data, later your developing theory will suggest to you where to go next to collect data and which, more-focussed, questions to ask; which is the deductive phase of the Grounded Theory process.