The mode of a set of data is the most frequent value. Sometimes there is more than 1 most frequent value so there is more than one mode.
For Jeune mannequin example our set is 1,2,3,4,4,5,6,9 the mode is 4 and here is another set 1,2,3,3,4,5,6,6,7 the modes are 3 and 6 and we say the set is bimodal.