Film deposition techniques frequently used for the preparation of MgB2 and high-Tc superconductor films are briefly presented. In polycrystalline high-Tc superconductors, high-angle grain boundaries act as weak links, and limit therefore the transport critical current density Jc. In contrast, the low-angle grain boundaries present in biaxially textured films do not block the supercurrents. The investigation of biaxially textured films provides information on the current carrying capacity in the absence of weak links. At low temperatures and zero applied field Jc values above 10 MA cm−2 have been reported for MgB2 and cuprate high-Tc superconductor films, while values between and 1 and 10 MA cm−2 have been achieved in iron-based superconductor films. The effects of film thickness and epitaxial strain on the critical temperature are described for selected examples. Finally, interfacial superconductivity is briefly considered.