This is the 15578th most frequent German word.
weiche
"Weiche" (noun) in English means "switch" (in railway context) or "softness/tenderness" (from the verb "weichen").
Here, 'weichen' (the dative plural form of 'weich', meaning 'soft') is used as an adjective to describe the noun 'Matratze' (mattress).
Ich liege gerne auf einer weichen Matratze.
I like to lie on a soft mattress.
'Weiche' in this sentence is a noun meaning 'switch' (in the context of railways). It is used in its singular form.
Die Weiche des Zuges wurde umgestellt.
The railway switch was adjusted.
'Weiche' is used as an adjective here, describing the bread rolls ('Brötchen') in a nominative plural context.