I briefly review the properties of the gas flow in and around the region of
the bar in a disc galaxy and discuss the corresponding inflow and the loci of
star formation. I then review the flow of gas in barred galaxies which have an
additional secondary bar. Finally I discuss the signatures of bars in edge-on
galaxies.Comment: 6 pages, 2 figures, style file incl., to appear in the proceedings of
an ESO/CTIO/LCO workshop "Stars, Gas and Dust in Galaxies : Exploring the
Links", eds. Alloin, Olsen & Galaz (ASP Conf. Series