Explain why companies have cash equivalents?

A cash equivalent is something that can be turned into cash in a short period of time, but is not cash at the time of the disclosure of it's value. So, in order to make a balance sheet a more manageable size and to make it easier to read and interpret, cash and cash equivalents are usually consolidated and reported as one figure or as two. (Imagine looking at a 50 line balance sheet if every type of highy liquid investment was disclosed as a single line item.) As to why a company would own one.... If excess funds were available the company's management may find they can put their cash to better use by investing it in various financial instruments... that are not technically cash (hence cash equivalents).