Crassula ovata is the Jade Plant, a succulent that slowly builds a thick woody trunk and can live for decades. Old specimens are passed down between generations.
Because it is a succulent, almost everything that is true for tropical houseplants is reversed here.
What every Crassula wants
Direct sun. Several hours a day, on a bright windowsill. In low light the stems stretch, the leaves space out, and the plant becomes floppy and weak.
Water thoroughly, then wait until the soil is completely dry throughout before watering again. In winter that can mean once a month or less.
Use a gritty cactus mix and a pot with drainage. Ordinary compost holds far too much water.
Crassula are toxic to cats and dogs.