Parallel lines are like best friends. They never cross each other and always stick by each other's side. Recognizing when two lines are parallel or perpendicular has everything to do with their slope. What determines if lines will be best friends or not? Look at the slope! If the linear equations have matching slopes, the answer is yes. However, looks can be deceiving and sometimes the only way to confirm the relationship between two lines is to compare not only Positive and Negative Slopes, but negative reciprocal slopes as well.
Learn this and go on to Finding the Equation of a Line given its Slope and a Point