An antenna doesn't create power — it focuses it in a specific direction, like a flashlight focuses light. Isotropic Antenna: Theoretical antenna that radiates equally in all directions (0 dBi gain). Used as a reference. Directional Antenna: Focuses energy in a specific direction. Higher gain = narrower beam = farther reach. Omni-directional: Radiates equally in the horizontal plane (like a donut shape). Used for small cells.