Transcranial magnetic stimulation (TMS), using strong time-varying magnetic fields to stimulate the brain non-invasively, is increasingly used as a mean to safely probe brain function and to alleviate symptoms associated with neurological disorders. TMS has indeed become a precious tool to understand brain function in healthy volunteers, and is actively explored as a novel diagnostic and therapeutic tool for a wide range of neurological disorders. We briefly review here the origins of TMS, its mechanisms of action and its most widely widespread research and clinical uses. We also mention the current limitations that TMS is facing, and how these challenges are motivating novel TMS developments. It appears plausible that TMS will represent, in the near future, a therapeutic option of choice, due to its possibility to non-invasively interfere over extended periods of time with abnormal patterns of brain activity associated to specific neurological disorders.