Hey sarah. There are 2 main groups of brain cells. The first are called neurons, these are cells that connect together and fire electricity to make us move, think and be conscious. Not all neurons are the same though, depending on where they are in the brain they control different functions and so look a bit different, some have lots of long spindly arms (called dendrites) others just have one or 2.
The other main group are called glial cells. These help support the neurons in different ways and there are 3 main types. Oligodendrocytes wrap round the long parts of the neuron that the electricity fires down, and protect it like the rubber coating on a metal wire. Microglia remove any infection and dead or damaged neurones. Astrocytes wrap around the blood vessels in the brain to stop any bacteria or chemicals passing into the brain.