Help with understanding Effect.Service dependencies

export class DecoderService extends Effect.Service<DecoderService>()('DecoderService', {
  effect: Effect.gen(function* () {
    const config = yield* DecoderConfig
    const devices = yield* DeviceRepository
    const events = yield* PayloadPublishingService

    return {
      handler: Effect.succeed((unknown: unknown, _context: Context) => Effect.gen(function* () {
        // ...
      })),
    }
  }),
  dependencies: [
    DecoderConfig.Default.pipe(
      Layer.provideMerge(DeviceRepository.Default),
      Layer.provideMerge(PayloadPublishingService.Default),
      Layer.provideMerge(DefaultPowerToolsLoggerLayer),
    ),
  ],
  accessors: true,
}) {}

    const layer = DecoderService.DefaultWithoutDependencies.pipe(
      Layer.provide(DecoderConfig.Default),
      Layer.provide(DeviceRepository.Default),
      Layer.provide(PayloadPublishingService.Default),
      Layer.provide(Layer.setConfigProvider(configProvider)),
      Layer.provide(DefaultPowerToolsLoggerLayer),
    )