Some of us who enjoy gardening may not like to admit how useful the internet can be. There is a lot of bad information out there. There is also some degree of good information. It is impossible to fit much information about apples into just a few brief paragraphs. Therefore, the internet is likely the best source of information about the countless cultivars and specie within the genus of Malus.
The most popular apple trees produce the familiar crisp and sweet fruit that ripens anytime between late summer and late autumn, depending on cultivar. The fruit is quite variable. Some cultivars are best for eating fresh. Others are best for cooking or juicing. Some are very sweet, while other are quite tart. Each fruit is about the size of a baseball, but can be much bigger or much smaller. Crabapples are very small. Flowering crabapples make only tiny fruits that are eaten by birds.
The trees are quite variable too. Semi-dwarf trees can be pruned to stay low enough so that all of the fruit is within reach from the ground. Standard trees that grow in orchards can get as big as shade trees. All fruiting apple trees need specialized pruning each winter so that they do not become overgrown and disfigured, and to control disease. All apples bloom sometime in early spring.