Bajar vs. descender

The Spanish words 'bajar' and 'descender' both translate to 'to go down' or 'to come down' in English. However, their usage can differ slightly based on context and regional influences.

Bajar

'Bajar' is a versatile verb used frequently in Spanish to express the act of going down or lowering something. It's often used in physical and figurative contexts.
Voy a bajar las escaleras.
(I'm going to go down the stairs.)
Por favor, baja el volumen de la música.
(Please, turn down the volume of the music.)
El sol está bajando en el horizonte.
(The sun is going down on the horizon.)

Descender

'Descender' usually has a more formal tone and is most commonly used in technical or formal contexts. It refers mostly to decreasing levels or values, or coming down from a higher position in a more abstract sense.
El acantilado desciende abruptamente hacia el mar.
(The cliff descends abruptly towards the sea.)
La economía va a descender este año debido a la pandemia.
(The economy is going to go down this year due to the pandemic.)
El río desciende de la montaña y fluye hacia el valle.
(The river descends from the mountain and flows into the valley.)

Summary

'Bajar' and 'descender' both mean 'to go down', however, 'bajar' is more commonly used for lowering things and descending stairs while 'descender' is predominantly used in formal contexts or when referring to lowering levels or values.