Masking: What is it?

I've come across the term 'masking' a few times, and I did a little google search. I'm still not sure I fully understand it.

Parents
  • I can mask well at times, holding a good conversation with Normies. But driving to do stuff puts the fear of God into me. I have lost control of the car before. That puts additional pressure on me. Plus, I despise queues and use back-roads whenever I can.

Reply
  • I can mask well at times, holding a good conversation with Normies. But driving to do stuff puts the fear of God into me. I have lost control of the car before. That puts additional pressure on me. Plus, I despise queues and use back-roads whenever I can.

Children