Simplify the following text for a Grade 10 native English-speaking person.
Original: Carbonated water ( also known as club soda , soda water , sparkling water , seltzer , or fizzy water ) is water into which carbon dioxide gas under pressure has been dissolved , a process that causes the water to become effervescent .
Simplified: Carbonated water , also known as sparkling water , fizzy water , seltzer , and water with gas , is plain water into which carbon dioxide gas has been dissolved .