(n.) An explosive device buried in the ground and designed to explode when triggered (either via command wire, pressure or other physical trigger) in the proximity of a vehicle (possibly full of squaddies), person (squaddies are prefered), or animal (squaddie again).
Mines are usually designed against a specific target type. A mine designed to destroy a vehicle will not be configured to generate a great deal of person inconveniencing shrapnel whereas a anti-personnel mine will be.
They are usually deployed as a defensive weapon to interdict an area but are also a favourite offensive weapon of guerillas who would use them to interdict road or rail routes.
What to do if you step on one
Where are they?
Once laid they are are often forgotten about leading to deep unpleasantness when the conflict is over for the civilian population.
The Landmine Monitor Report is published every year (both in hard copy and on-line) and gives comprehensive information regarding the situation of landmines, UXO, victims, clearance and treaty obligations (under MBT and CM Treaty soon to be incorporated). If you are travelling to an affected country for holiday, work or even deployment, you may find this a useful reference tool for information: