Inductive and deductive reasoning are essentially opposite ways to arrive at a conclusion or proposition. The main difference between inductive and deductive reasoning is that while inductive reasoning begins with an observation, supports it with patterns and then arrives at a hypothesis or theory, deductive reasoning begins with a theory, supports it with observation and eventually arrives at a confirmation.
Inductive reasoning relies on patterns and trends, while deductive reasoning relies on facts and rules. Inductive reasoning follow a flow from specific to general, deductive reasoning flows from general to specific. You might use inductive reasoning when attempting to understand how something works by observing patterns. Deductive reasoning, on the other hand, might be more helpful when defining and establishing relationships between two or more entities.