For most of us beer glossary it’s all about differences between tastes and flavours but there is many more technical and procedures differences.
Type of yeast: Ales are made with top-fermenting yeast, whereas lagers are made with bottom-fermenting yeast. This makes a lot of difference to the finished product.
- Temperature: Ales are fermented at temperatures from 15 to 25 deg C. Ales are matured for shorter periods and at warmer temperatures. On the other hand, Lagers, will ferment at cold temperatures less than 10 deg C.
Colour: Ales are Reddish brown or dark brown. Although, the colours can be lighter in pale ales. Lagers range from very light to very dark depending on style.
Flavour: Ales are usually described as “robusty, hearty and fruity”. Lagers are characteristically “smooth, elegant, crisp, and clean”. This can vary a lot depending on the types.
Examples:
Ales: http://www.thedrinkscabinet.co.uk/cat/ale
Lagers: http://www.thedrinkscabinet.co.uk/cat/lager