This document discusses the uses of "will" and "would" in the English language. "Will" is used for real situations and future plans that are likely to happen, such as stating that "I will visit my parents next year." "Would" is used for hypothetical or assumed situations that are difficult to achieve, like saying "It would be very cold on the moon" or "If I were rich, I would buy a castle." The document provides examples of sentences using both "will" and "would" to illustrate their proper uses.