This is the 1492nd most frequent Spanish word.
subir
"Subir" means "to go up," "to climb," or "to rise."
In this sentence, 'subir' is used to indicate physically ascending an object, the mountain.
Voy a subir la montaña esta tarde.
I am going to climb the mountain this afternoon.
Here, 'subir' conveys the action of increasing a measurable quantity, in this case, volume.
Por favor, ¿puedes subir el volumen de la televisión?
Please, can you increase the volume of the television?
In this context, 'subir' refers to sending data from a local system to an online platform or server.