"Una computadora" is one of the regional expressions for "computer". Others can be "un computador", or "un ordenador".
They mean, "to use the computer".
Computadora
Is there a computer in your class?
La computadora
the student (female) wants a new computer.
a blonde (woman)
That is Spanish for "There is a girl".
"A computer"
¿Tiene usted un ordenador/una computadora? -formal ¿Tienes un ordenador/una computadora? -informal
Es sólo una computadora.
To say 'I want a computer' in Spanish, you would say 'Yo quiero una computadora.'
You say, "Trabaja por una empresa computadora."
Is there a computer in your class?
As a statement it means "you have a computer" As a question it means "Do you have a computer?"
On top of the computer
it means: computer. another word for computer is computadora
You can say "(Él) va a jugar con una computadora en la noche" (as a future action).
"Is there a computer in your class?"
computadora