Help understanding query keys

import { useQuery } from '@tanstack/react-query'
import { createClient } from '@/lib/supabase/client'

export function useAllCafeRatings() {
  return useQuery({
    queryKey: ['cafe_ratings', 'all'],
    queryFn: async () => {
      const supabase = createClient()
      const { data, error } = await supabase
        .from('cafe_ratings')
        .select('*')
        .order('created_at', { ascending: false })
      if (error) throw error
      return data ?? []
    },
  })
}

export const qk = {
  cafes: {
    nearby: (lat: number, lng: number, limit: number) =>
      ['cafes', 'nearby', lat, lng, limit] as const,

    detail: (cafeId: string) =>
      ['cafes', 'detail', cafeId] as const,
  },

  ratings: {
    byCafe: (cafeId: string) =>
      ['ratings', 'byCafe', cafeId] as const,
  },
} as const