Computers contain series of sequential systems that they have to follow in order to finish a command. Meaning, before they execute a single command a controller must enter a signal therefore it cannot generate a new command or signal that was not programmed inside. Humans on the other hand have the capability to decide and create new ideas depending on the scenario. The brain contains billions of connections to every part of the body that allows movements and work. The brain also has the ability to create certain response to any stimuli the human is experiencing. Both has the capacity to store memory; computers have defined size of memory humans have different kinds of memory.
First of all computers don't think. They are simply machines that follow certain protocols. The human brain consists of billions of neurons that send and receive signals. There are as much cells as the neurons that support in the activity of neurons. These cells are responsible for our thought, memories. The human brain is a complex organ.