A binary string is a string that represents a number in binary format and only contains 0 and 1. Supposing we have a number 3, the binary string will be 11, or the binary string of 9 is 1001.
Binary string is usually used to hold non-traditional data, such as pictures. Suppose we have the following black and white image:
If black is represented by 0 and white is represented by 1, we can create the following binary string to represent the preceding image:
111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111000000000011111111111111 ...