I know this question may sound a bit basic, but it is actually quite interesting. We know the two forms of energy are potential energy and kinetic energy, and that these forms of energy can be in many forms (e.g. thermal energy, elastic potential energy, gravitational potential energy...). However, what I don't really understand is, how is this energy actually stored? By this I mean, for example, how is kinetic and potential energy stored in terms of particles. Has it got to do with the amount of vibration or the separation between the particles? Also, if matter is equivalent to energy is matter therefore a form of energy? I'm sorry if it sounds confusing but I just find energy a really hard concept to visualise, it's not something easy to visualise such as matter. I would appreciate any help given.