The English words "and" and "or" are conjunctions, and they have a few different forms in Spanish.
And = y, e
"And" is normally translated as y:
|José y Ana hablan francés.||José and Ana speak French.|
|Me gustan las fresas y las frambuesas.||I like strawberries and raspberries.|
|Necesitamos sal y hielo.||We need salt and ice.|
When "and" precedes a word that begins with the sound [i], the Spanish translation is e instead of y, in order to avoid having two "i" sounds in a row. This includes words that begin with i and hi, but not words that begin with hie.
|Hay templos e iglesias en este calle.
||There are temples and churches on this street.|
|Todos mis hijos e hijas han ido a la universidad.||All of my sons and daughters have gone to college.|
Or = o, ó, u
"Or" is normally translated as o:
|¿Quieres café o té?||Do you want coffee or tea?|
|Paco o David puede ayudarte.||Paco or David can help you.|
When "or" precedes a word that begins with the sound [o], the Spanish translation is u instead of o, in order to avoid having two "o" sounds in a row. This includes words that begin with o and ho.
|Hay siete u ocho estudiantes en la oficina.||There are seven or eight students in the office.|
|¿Es vertical u horizontal?||Is it vertical or horizontal?|
When o is used with numerals, it becomes ó, to avoid confusion with the number 0.
|2 ó 3||2 or 3|
|9 ó 10||9 or 10|
Note for French speakers
I’ve always found it interesting that the alternate forms e and u sound like the French conjunctions et and ou.