Boda vs. casamiento

The terms 'boda' and 'casamiento' both refer to the concept of a wedding in Spanish. In general, both words can be used interchangeably without changing the meaning of the sentence. However, their exact usage often varies based on regional dialects.

Boda

This term is the universal Spanish word for 'wedding'. It is widely understood and used in all Spanish-speaking countries.
Invitamos a todos nuestros amigos a nuestra boda.
(We invited all our friends to our wedding.)
La boda será en junio próximo.
(The wedding will be next June.)

Casamiento

'Casamiento' also means 'wedding', but its usage is more prevalent in some areas than others, like in Argentina, Uruguay and Paraguay. It is less commonly used in other Spanish-speaking regions.
Todo estaba listo para el casamiento.
(Everything was ready for the wedding.)
El casamiento será una gran fiesta.
(The wedding will be a big party.)

Summary

While 'boda' and 'casamiento' are both Spanish words referring to a wedding, their use can vary based on regional differences. 'Boda' is universally understood throughout the Spanish-speaking world, while 'casamiento' is more commonly used in countries like Argentina, Uruguay, and Paraguay.