I know gator-aid and its like advertise that they have lots of them. And I know sometimes I feel bad if I sweat a lot and just drink water. But are they just advertising… salt? Are there different kinds of electrolytes, and if so are they interchangable?
When dissolved in water many atoms and molecules have some charge, that allows them to create relatively weak bonds with waters (therefore stay in solution).
The charge means that they have either more electrons than protons (negatively charged) or less (positively charged). These are called electrolytes because they can be “moved” in water and separated by applying an electrical field (electrolysis, this requires a different eli5, take it as it is).
Outside water these substances aggregate to form “salts”.
Now, some of these charged elements are crucial for functioning of basic biological processes, such as thinking, muscle contraction (including heart), even sensing.
Unfortunately they are lost when sweating (they are dissolved in sweat). In a healthy diet, where you eat enough fruit and vegetables, this is not an issue. If you are doing intense exercise however, an additional dose of these substances might help. TBF I am not sure if it has ever been proved that it is necessary… But it might help.
As said, if your diet is good, you don’t need them. If your diet is s*it you’ll probably have other issues. If you have real issues your doctor will tell you how to address them.
Tl;dr: those drinks are marketing stuff. They might be beneficial only in case of intense physical exercise, not needed for daily life if you follow a healthy diet