Did we evolve from apes? What does the term 'common ancestor' really mean?

You are related to all the humans that are currently living on the planet, even if distantly. However, you are more closely related to your first cousin than you are to a classmate of yours. This is because you both have the same grandmother: you share a more recent ancestor with your cousin than you do with your classmate. This is what is called a 'common ancestor': you have your grandmother 'in common' with your cousin. When we talk about common ancestors in evolution, we're talking about the same principle but on a larger scale, and we're talking about ancestors from long ago (about 6 million years). Before either chimpanzees or humans as we know them existed, there lived a creature, an ape, that is an ancestor of ours as well as an ancestor of chimpanzees. That common ancestor produced offspring, that at some point split into two groups. Those two groups were part of the same species, but over time, over many generations of being separated, they became different to one another so that they no longer interbred. These two groups became different by chance, and different by adaptation to the different environments they found themselves in. Those two separate lineages (groups) changed over six million years and split again and again (where Homo erectus and others fit in). The surving species from those two lineages that split are Homo sapiens (us) and chimpanzees. That common ancestor lived more recently than the common ancestor that we and chimpanzees share with gorillas. This means that chimpanzees are more closely related to us than they are to gorillas, however surprising that may seem.