The mode is the value that appears most often in a set of data.

Example: A= { 1,2,3,4,5,5,6,7,8,9,9,9}

The mode of this data set is the number  9 that repeat 3 times.

In case there are 2 numbers that repeat the same number of times we say the data set is bimodal while a set with more than two modes may be described as multimodal.