Inquire can operate as a small floating Window, which functions as a desk accessory. You can drag and drop calculations, conversions, and other inquiries to its target and receive your result via the clipboard (just paste the result), as illustrated below.
Most may want to use it as an Application. To do this, single click the target and it expands to the Application mode shown 2/3 scale below:
Various Inquire 'Action' choices are shown on the left below. On the right are three buttons each displaying possible words, numbers, formulas, or phrases which you could use with Inquire. The result of each inquiry will be displayed below the button set.