There are two sliders in Lightroom and most other post-processors that can be handy for adjusting the intensity of your colors.
Think of saturation like ISO, but for color — it bumps up the intensity of all of the colors in your photograph. On the other hand, vibrance is more selective, adjusting only the more muted colors in your photograph. This can help lead to a more evenly-saturated image. Both tools definitely have their usage — check out the three photos below to see how they can affect an image.