peanut butter and jam sandwich in the UK, Canada and Australia, is a sandwich that includes a layer of peanut butter and either jelly or jam on bread, commonly between two slices, but sometimes eaten open-faced, that 
is, with peanut butter and jam or jelly on each of two slices, eaten without putting the two slices together and without folding each slice of bread.
Peanut butter is a food paste made primarily from ground roasted peanuts, with or without added oil. It is popular throughout the world and is also manufactured in some emerging markets. Its primary use is as a sandwich spread.
In some types of gourmet peanut butter, chocolate or other ingredients may be added. Various nut butters are also made from other nuts.
Jam contains both fruit juice and pieces of the fruit’s (or vegetable’s) flesh,however some cookbooks define Jam as cooked and gelled fruit (or vegetable) purees.
Properly, the term jam refers to a product made with whole fruit, cut into pieces or crushed. The fruit is heated with water and sugar to activate the pectin in the fruit. The mixture is then put into containers.
The peanut butter and jelly sandwich is very popular with both adults and children in the US and Canada. A 2002 survey showed the average American will have eaten 1,500 of the sandwiches before graduating from high school.Jars of pre-mixed peanut butter and jelly are commercially available for making these sandwiches.
taken from: FunRose
