KNO₃ and H₂SO₄ are classified as electrolytes since they dissociate in water. KNO₃ in water goes to K₊ and NO₃⁻. H₂SO₄ in water can be thought of as going to 2H⁺ and SO₄²⁻ but later on you will learn that when placed into water, H₂SO₄ actually forms H₊, HSO₄⁻, and SO₄²⁻ since HSO₄⁻ is a weak acid and won't dissociate completely.
I hope this helps and if anything is unclear feel free to ask about it in the comments.