Enantiomers are mirror image molecules which have different effect. For example spearmint and caroway are enantiomers.
Isomers, Enantiomers and Chiral Carbon
A Chiral Carbon is one which does not exhibit symmetry. For more information and a test see:
http://www2.vuw.ac.nz/staff/paul_teesdale-spittle/organic/chiral_web/main.htm