As @julienneviuya described Design History File (DHF) is created during the Design Phase during the product development stage of the device and is written before the production. Whereas the Design History Record (DHR)is produced during the Production Phase and is a record of everything done to a single device or a single lot/batch of devices, which ensures traceability. It defines how the lot should be produced to meet the spec, gives tolerances, tells you what to do if things go wrong, verifies the quantities of ingredients, shows the release for sterilization, has a section for documenting QC, and a section doe QA review of the documentation and the product cannot be released unless DHR is signed off. The Device History Record is the evidence that a particular unit, batch or lot of devices was made according to the specifications laid out in the DMR.