Let's look at the following images_

Now compare the following images

with the previous ones_

What do these pictures have in common?_

declare function fastify<
  Server extends http2.Http2SecureServer,
  Request extends RawRequestDefaultExpression<Server> = RawRequestDefaultExpression<Server>,
  Reply extends RawReplyDefaultExpression<Server> = RawReplyDefaultExpression<Server>,
  Logger extends FastifyBaseLogger = FastifyBaseLogger,
  TypeProvider extends FastifyTypeProvider = FastifyTypeProviderDefault
> (opts: fastify.FastifyHttp2SecureOptions<Server, Logger>): FastifyInstance<Server, Request, Reply, Logger, TypeProvider> & SafePromiseLike<FastifyInstance<Server, Request, Reply, Logger, TypeProvider>>

declare function fastify<
  Server extends http2.Http2Server,
  Request extends RawRequestDefaultExpression<Server> = RawRequestDefaultExpression<Server>,
  Reply extends RawReplyDefaultExpression<Server> = RawReplyDefaultExpression<Server>,
  Logger extends FastifyBaseLogger = FastifyBaseLogger,
  TypeProvider extends FastifyTypeProvider = FastifyTypeProviderDefault
> (opts: fastify.FastifyHttp2Options<Server, Logger>): FastifyInstance<Server, Request, Reply, Logger, TypeProvider> & SafePromiseLike<FastifyInstance<Server, Request, Reply, Logger, TypeProvider>>

declare function fastify<
  Server extends https.Server,
  Request extends RawRequestDefaultExpression<Server> = RawRequestDefaultExpression<Server>,
  Reply extends RawReplyDefaultExpression<Server> = RawReplyDefaultExpression<Server>,
  Logger extends FastifyBaseLogger = FastifyBaseLogger,
  TypeProvider extends FastifyTypeProvider = FastifyTypeProviderDefault
> (opts: fastify.FastifyHttpsOptions<Server, Logger>): FastifyInstance<Server, Request, Reply, Logger, TypeProvider> & SafePromiseLike<FastifyInstance<Server, Request, Reply, Logger, TypeProvider>>

declare function fastify<
  Server extends http.Server,
  Request extends RawRequestDefaultExpression<Server> = RawRequestDefaultExpression<Server>,
  Reply extends RawReplyDefaultExpression<Server> = RawReplyDefaultExpression<Server>,
  Logger extends FastifyBaseLogger = FastifyBaseLogger,
  TypeProvider extends FastifyTypeProvider = FastifyTypeProviderDefault
> (opts?: fastify.FastifyHttpOptions<Server, Logger>): FastifyInstance<Server, Request, Reply, Logger, TypeProvider> & SafePromiseLike<FastifyInstance<Server, Request, Reply, Logger, TypeProvider>>