Micromanagement, frequently referred to as micro, involves focusing on individual units in battle, preserving and making the most use of the units.
For instance, dancing is a micromanagement strategy, and can be described as such: attacking with 10 dragoons with 2 in front and 8 in back. When the 2 in front are about to die, bring the 2 back behind the 8 to save units. The enemy wastes time attacking the 2, and end up having to kill the other 8.
Blizzard staff. Glossary. Blizzard Entertainment. Accessed 2009-12-13.