The cytoskeleton is basically the structure of a cell. so the bones, but its also the means of transportation.
Actual definition: a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence. Also the reason its made this way it to maintain structure by webbing the cell.
a cytoskeleton represents a channel system like bcits hallways it structures all the walls and if you think about it is a skeleton.
Bibliography: http://www.cytoskeleton.com/ http://www.nature.com/scitable/topicpage/microtubules-and-filaments-14052932