The difference between a lizard and a salamander is that a lizard is a reptile and a salamander is an amphibian. Reptiles live solely on land, while amphibians spend part of their time in the water. Hence amphibians need to be near a source of water while reptiles don't.
The skin of a salamander is soft, permeable and lacks scales. Like other amphibians, salamanders secrete mucous over their skin to help it retain moisture. Some salamanders have potent toxins in their skin. They lay their shell-less eggs in jelly-like masses either in still water or in a moist place like leaf mold. The eggs hatch into larvae who live in the water and breathe through gills. As they grow, their lungs develop and they are able to leave the water and breathe air. Some salamanders, however, retain their gills even in adulthood.
Lizards have scaly skin that helps them keep in water. They don't need to live near ponds, lakes or streams, and many species of lizards live in deserts. Their eggs are amniotic and are protected by shells that are hard or leathery. When the eggs hatch, the young are miniatures of their parents and don't undergo metamorphosis. Lizard toes are clawed, which is not true for salamanders.