Theory is a group of ideas or perceptions used to explain something usually based on the theorists perspective
I use theory in my everyday life to help me understand things from the perspective of others and to understand the relationship between theory and social life.
A theory is an idea or set of ideas that explain and/or understand something. A theory could be something simple like “I have a theory that you took the last cookie from the jar!” to “Playing chess moves on both sides of the board, as opposed to just one side, will stretch out your opponents defence and make it easier to attack”.
An example of an interesting set of Theories is chess openings. If you have ever heard a chess player talk about them, they sound mysterious. They talk about strange things like the “Budapest Gambit”, or “The Sicilian”, or the “Smith-Mora” and seem to know what they are! What each of those names represent is a set of Theoretical moves and ideas that attempt to answer the question: What is the best set of moves to start the game with in chess? Each ‘Opening’ as they are called has a different perspectives and ideas about how a game of chess should be played, just like different sociological theories have different explanations of behaviors and ideas underlying them.