Esposo and Marido are almost the same.
Esposo is partner with legal status, married by law.
Marido is also that, but some people use it as if you have a partner but aren't married. Like common law.
So If I have a common law partner.
I can say,
El es mi marido. ( pero no esposo. )
How about Wife?
You can say Esposa, but can't Marida.
Marida doesn't exist.
You can say "Mujer".