signed vs. unsigned | two's complement | Sign & magnitude
Machines must be able to represent signed and unsigned values that are very important data type used in programming languages. Two's complement is a representation that can represent singed and unsigned numbers very efficiently. This video clarifies key concepts of a two's complement binary representation and it goes on to give a detailed account on how to calculate the ranges of values for both signed and unsigned numbers using the number wheel. It goes on to compare two methods of representing negative numbers, i.e. sign and magnitude (S&M) method with two's complement representation.
The video gives a graphical visualization to highlight the shortfalls and limitations of the sign and magnitude scheme of encoding negative numbers. The video then goes on to explains how the two's complement waives off the disadvantages of the S&M encoding method with examples.