CRT is a rather old academic theory from the 70s, regarding systemic racism in the US. From my understanding, it was initially used to instruct law students so, I assume, when they were representing Black clients they would understand the racist elements in the system. That's just my interpretation from the little I've read about it. It's just been dusted off the shelf and discussed more openly recently.
But, in today's crazy world, CRT is a symbol, grossly exaggerated by the far right, hoping to use it to defeat Democrats in the midterms. They are portraying CRT as a commonly taught theory used in public schools, to indoctrinate white children to be full of guilt, as all white people, including that cute little 5 year old blonde girl, are responsible for every racist act towards Black people since the time of slavery. Of course, that's made up propaganda. CRT isn't even taught in the public schools, but the Repugs have believed the lies and their dear leaders are passing laws against teaching it in public schools. Oh, the horror. We can't tell our children the darker side of American history. We must white wash the dark side of US history, and proudly rent our minds to the US flag, while chanting....USA....USA.....USA.
At least that's how I see it. Opinions may vary.