The term electrolyte is a term used when talking about solutions with water as the solvent. We demonstrate the property of being an electrolyte with an electrical conductivity tester like this.
Pure water does not conduct electricity. I will put the electrodes of this apparatus into a beaker of pure water. There is no light coming from the light bulb. If I dissolve a material in this water and the light lights brightly, the dissolved material is called a strong electrolyte.
As an example, here is a small amount of table salt. As I add it to the water and dissolve it, it dissolves by breaking into charged particles, the ions of sodium and chlorine, which now allow the solution to conduct electricity. So the ionic substance table salt is a strong electrolyte
The term non-electrolyte refers to a substance which dissolves in water but does not allow electrical conductivity. Here is some water and some sugar. As the sugar dissolves, the light does NOT light up. So sugar is a non-electrolyte.
Some acids and bases are also strong electrolytes. Here as an example is some hydrochloric acid. Only a little in the water allows the light to light up very brightly. So the acid is also a strong electrolyte and is called a strong acid.
Acetic acid, on the other hand, dissolves but allows very little electricity to go through the water. See how the light bulb gives off much less light. Thus we call acetic acid a weak electrolyte and a weak acid.
