Java BitSet is a class that implements a growable array of bits. It provides methods for manipulating individual bits or groups of bits, making it a useful tool for bit-level operations, such as compression algorithms, flags, or binary data manipulation. Introduced in Java 1997 with Java 1.2, BitSet is part of the Java collections framework, enabling efficient handling of large amounts of binary data, especially when the number of elements is not known in advance.

https://docs.oracle.com/javase/8/docs/api/java/util/BitSet.html