What is Eureka service, Eureka Client, Eureka instance and Eureka server
<p>I'm learning spring cloud Netflix by reading <a href="http://cloud.spring.io/spring-cloud-netflix/spring-cloud-netflix.html" rel="noreferrer">this article</a>, however I started to get confused by different terminology in this article, they are:</p>

<ol>
<li><p><strong>Eureka service.</strong> To my understand it's an ordinary service (specifically a Microservice) that running on a unique uri (i.e.one service per uri). Say <code>localhost:12000</code>. It is can be registered in the Eureka server.</p></li>
<li><p><strong>Eureka Client.</strong> Same thing as Eureka service???</p></li>
<li><p><strong>Eureka Server.</strong> To my understand, it's the server that we can inspect, discover and manage bunch of Microservices we built, normally running on <code>localhost:8761</code></p></li>
<li><p><strong>Eureka Instance.</strong> I'm confused by what's it referred to, same thing as the Eureka client? </p></li>
</ol>

<p>Also in this article, it mentions <code>eureka.client</code> in config and <code>EurekaClient</code> in Netflix API, are they referring to the same thing? </p>

<p>Please tell me what do these four terms mean and correct me if I'm wrong. Thank you! </p>

<p>==================================UPDATE==================================</p>

<p>In the article it said: </p>

<blockquote>
  <p><code>@EnableEurekaClient</code> makes the app into both a Eureka "instance" (i.e.
  it registers itself) and a "client" (i.e. it can query the registry to
  locate other services).</p>
</blockquote>

<p>So it looks like the Eureka instance is same as Eureka service. While Eureka Client is a special instance that can query for other instances/services.</p>