Mermelada vs. confitura
The Spanish words 'mermelada' and 'confitura' both refer to sweet spreads usually made from fruit. Although they are often used interchangeably, they do have subtle differences in their usage and connotations in different regions.
Mermelada
'Mermelada' typically expresses a broad term for any kind of sweet fruit spread. The word is commonly used in most Spanish-speaking regions. 'Mermelada' can contain chunks of fruits as well.
Me gusta la mermelada de fresas en el pan tostado.
(I like strawberry jam on toast.)
En el desayuno comeremos pan con mermelada de naranja.
(For breakfast we will eat bread with orange marmalade.)
Confitura
'Confitura' is a term used more in Spain than in Latin America. While it also refers to a sweet fruit spread like 'mermelada', many critics argue that 'confitura' should be a preserve with a much higher fruit content or contain whole pieces of fruit.
La confitura de cerezas está deliciosa.
(The cherry jam is delicious.)
Compré una confitura de manzana para el postre.
(I bought an apple preserve for dessert.)
Summary
'Mermelada' and 'confitura' are both Spanish terms for sweet fruit spreads, like what English speakers would call 'jam' or 'preserves'. However, while 'mermelada' is a general term use widely, 'confitura' is more specific and tends to indicate a high fruit content or whole pieces of fruit within the spread. This latter term is used more frequently in Spain than Latin America.