Yes, true. Cause and effect writing shows a connection of how or why one thing causes or affects another. For example, let's say you're writing about global warming. You could write about the causes of global warming and/or the effects of global warming.
The effects of global warming are the melting of the polar ice caps, climate change, and the destruction of habitats for animals.
The causes of global warming are the use of fossilized fuel, the greenhouse effect, and the depletion of the ozone layer.
However you write a cause and effect essay, you are showing a relationship in which you show how or why A causes B or how or why A is the effect of B.