This article is from the Food Preserving FAQ, by Eric Decker ericnospam@getcomputing.com with numerous contributions by others.
Blanching is plunging your item(s) in boiling water for a short amount
of time (30 sec to 5 min, check your recipe), cooling the items quickly,
then drying off the items. You don't cook the item, but you kill off the
surface bugs and you destroy several important enzymes that brown and
degrade foods.
 
Continue to: