Radical acceptance is the idea of accepting a situation or stage in life as is without judgement. It's about not resisting those things you cannot change.
It doesn't mean you are condoning the situation or even like the situation but it allows for less emotional distress and entanglement by accepting everything as is.
Ultimately, we can't always control what happens in our lives but we have the power to control how we *respond* to it.
For me, radical acceptance has been a practice for a few years and it can be particularly helpful around the holiday times. Yet, sometimes I find myself stumbling to put it in place and really accept things as is, therapists are human just like you, I promise!