Dipolar chains formed in magnetic fluids out of colloidal magnetic grains have much in common with polymer molecules. An investigation of spatial and orientational intrachain correlations and elucidation of an important role of the chains flexibility lead us to natural and fruitful extension of basic concepts of polymer physics to the case of dipolar chains. Conformations of the chains (statistical coil, globule) in zero and infinitely strong external magnetic field are studied and the possible coil-globule phase transition is predicted and discussed.