Sometimes called blue-tailed skink, but don’t confuse it with the one native to Australia. This is Plestiodon fasciatus, better known as the common 5-lined skink. It’s one of the most common lizards in the eastern part of the US. Only the juveniles have this characteristic blue tail.
I could write more, but I’ve no pretensions of being an herpetologist and would just be parroting information read elsewhere. Here’s a nice little writeup about this reptile. Here’s another.