Ales vs. Lagers
Both ales and lagers are brewed in a wide variety of styles from strong and rich (barleywine and dopplebock) to crisp and hoppy (IPA and pilsner). The main difference between the two comes from the type of yeast used and the fermentation process. Ales are fermented at room temperature and typically have a noticeable amount of fruity-smelling esters due to this warm fermentation. The fruitiness can be subdued - as in a dry stout or dominating as in a barleywine.
Lagers on the other hand, lack any fruity character and may be crisp and hoppy like a pilsner or sweet and malty like a dopplebock. Both ales and lagers are malty, but this character can vary from a minimal light toast/biscuit note to a thick and chewy symphony. Figure 111 is a chart that attempts to visually represent the similarities and differences between beer styles.
Figure 111 - Relative Flavors of Beer Styles This chart is not to any scale but is a subjective attempt to describe how different beer styles taste relative to one another. As an over-simplification, a beer may be Malty - Sweet, Malty - Bitter, Fruity - Sweet, or Fruity - Bitter. Each beer style was placed on the chart via a great deal of "arm waving". The flavors often overlap between styles, and the variation within a single style can often bridge the positions of the styles next to it. This chart also fails to describe a beer's intensity. Some beer styles like Imperial Stout and Barleywine can literally cover half the chart in their complexity. A beer like Coors Light? would be smack-dab in the middle (and probably on another plane behind the chart). As I said above, this is an oversimplified attempt to give you a first glance at how a lot of the beer styles relate to one another.