Pressure refers to the force applied per unit area. In terms of increasing the rate of a reaction, an increase in pressure can speed up reactions involving gases by bringing particles closer together, leading to more frequent collisions and therefore faster reactions.
A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It works by providing an alternative pathway with lower activation energy for the reaction to occur, making it easier for reactant molecules to transform into products.
Temperature is a measure of the average kinetic energy or motion of particles in a substance. Increasing temperature generally leads to an increase in reaction rate because higher temperatures provide reactant molecules with more energy, resulting in more frequent and energetic collisions between particles.