Using technical terms correctly is a big step forward in being able to really understand what is being written about antennas (or other technical subjects). For the beginner, here is a simple explanation of these three terms: Resonance is a noun, the state of being resonant. "The antenna must be pruned for resonance." Resonate is a verb, indicating action. "When we prune an antenna, we resonate it." Resonant is an adjective, giving a description. "Once the antenna is pruned, it is a resonant antenna." Hope this helps.