Abstract: High temperature superconductivity is one of the unresolved problems at the cutting edge of condensed matter physics, stimulated greatly by the recent discovery and studies of iron-based superconductors. Here we briefly review the history and basic concepts of superconductivity,and the status of current research on copper-oxide high temperature superconductors. We will explain why iron-based superconductivity is so important as a key bridge between conventional and high temperature superconductivity, and remark, in particular, on the significant contributions from China.