It's about people not pixels
Ask 100 designers what the question "What is design?" and you will likely get 100 different answers, but this is how I see it:
Design is a process, not just a final lick of paint you put on an otherwise finished product. It's about continuous discovery and learning in the service of others. It's about people, not pixels.
Design is being intentional and pragmatic in approach, while in the service of real people - complicated, messy, and imperfect as they may be. The approach, tools and techniques may vary, but at it's core it means learning about those for whom you’re designing, gaining insight into their lives, and working to address the needs and/or opportunities you identify.