Eluent/Elution: The process by which analytes are washed out from a column by flowing solvent(s), similar to how passengers can be moved along by conveyor belts.
Flow Rate: How quickly your mobile phase moves through your column, akin to speed settings on an airport's conveyor belt.
Gradient Elution: A technique where concentration of solvent changes during separation process. It’s like changing speed of conveyor belt to separate people based on their walking speed.