In July 2016, the EU issued a revised guidance document on standalone software. The document is MedDev 2.1/6 Guidelines On The Qualification And Classification Of Stand Alone Software Used In Healthcare Within The Regulatory Framework Of Medical Devices.
The revision defines the term software as “a set of instructions that processes input data and creates output data”. It also has definitions for input data and output data.
Obtain a copy from https://ec.europa.eu/growth/sectors/medical-devices/guidance_en