Temperature is a scale used to measure heat. Heat is a basically how much overall kinetic energy molecules have in whatever it is you are studying. Put another way, it is the total energy of molecular motion in a substance (that's kinetic energy...the energy of motion) and is dependant on the speed of the particles, the number of particles (the size or mass), and the type of particles in an object. Temperature is a measure of the average energy of molecular motion in a substance and does not depend on the size or type of object.
So, if you are comparing two containers, say a cup of water and a pool filled with water, they can both have the same temperature, but the pool will have more heat energy because there are more particles.