Aquarium (100% Water)
Purely aquatic. Fish, shrimp, and aquatic plants. No land area.
Examples: planted tanks, cichlid tanks, shrimp tanks.
Vivarium (100% Land)
Purely terrestrial. Reptiles, amphibians, tropical plants. Water dish but no pool.
Examples: gecko vivarium, dart frog enclosure.
Paludarium (Mixed)
Combines water and land sections. Aquatic fish + land-based animals.
Examples: mudskipper paludarium, frog + fish community tank.
Pick Based on Interest
Love fish? Aquarium. Love reptiles/amphibians? Vivarium. Love both? Paludarium.
Paludariums are the most complex but most visually stunning.