The brain is composed of two nearly mirror-image lobes called the left and right hemispheres. The left hemisphere receives most inputs from and controls mostly the right side of the body. This hemisphere in humans is also specialized for language, rule-based reasoning, and analytic skills. The right hemisphere deals with the left side of the body, and it is better at visual pattern recognition and more holistic kinds of perception.
In most tasks, the two hemispheres use a divide-and-conquer strategy, where the left hemisphere processes the details, and the right takes in the big picture. The two hemispheres are connected by the largest fiber tract in the brain, the corpus callosum, which contains 200 million fibers.