REST最好被描述为与资源一起工作，而RPC更多地是关于操作。

休息 代表具象状态传输。这是一种组织独立系统之间交互的简单方法。 RESTful应用程序通常使用HTTP请求来发布数据(创建和/或更新)、读取数据(例如，进行查询)和删除数据。因此，REST可以将HTTP用于所有四个CRUD(创建/读取/更新/删除)操作。

RPC 主要用于跨不同模块通信，以服务用户请求。 例如，在openstack中，nova、glance和neutron在启动虚拟机时是如何协同工作的。

在HTTP上，它们都只是HttpRequest对象，它们都期望返回一个HttpResponse对象。我认为人们可以继续用这种描述来编码，而不用担心其他的事情。

这里有很多很好的答案。我仍然建议你参考谷歌的这个博客，因为它在讨论RPC和REST之间的区别方面做得非常好，并抓住了一些我在这里的任何答案中都没有读到的东西。

我想引用同一链接中的一段话，这段话让我印象深刻:

REST itself is a description of the design principles that underpin HTTP and the world-wide web. But because HTTP is the only commercially important REST API, we can mostly avoid discussing REST and just focus on HTTP. This substitution is useful because there is a lot of confusion and variability in what people think REST means in the context of APIs, but there is much greater clarity and agreement on what HTTP itself is. The HTTP model is the perfect inverse of the RPC model—in the RPC model, the addressable units are procedures, and the entities of the problem domain are hidden behind the procedures. In the HTTP model, the addressable units are the entities themselves and the behaviors of the system are hidden behind the entities as side-effects of creating, updating, or deleting them.

正如其他人所说，一个关键的区别是REST url以名称为中心，而RPC url以动词为中心。我只是想包括这个清晰的例子表来证明:

---------------------------+-------------------------------------+--------------------------
 Operation                 | RPC (operation)                     | REST (resource)
---------------------------+-------------------------------------+--------------------------
 Signup                    | POST /signup                        | POST /persons           
---------------------------+-------------------------------------+--------------------------
 Resign                    | POST /resign                        | DELETE /persons/1234    
---------------------------+-------------------------------------+--------------------------
 Read person               | GET /readPerson?personid=1234       | GET /persons/1234       
---------------------------+-------------------------------------+--------------------------
 Read person's items list  | GET /readUsersItemsList?userid=1234 | GET /persons/1234/items 
---------------------------+-------------------------------------+--------------------------
 Add item to person's list | POST /addItemToUsersItemsList       | POST /persons/1234/items
---------------------------+-------------------------------------+--------------------------
 Update item               | POST /modifyItem                    | PUT /items/456          
---------------------------+-------------------------------------+--------------------------
 Delete item               | POST /removeItem?itemId=456         | DELETE /items/456       
---------------------------+-------------------------------------+--------------------------

笔记

As the table shows, REST tends to use URL path parameters to identify specific resources (e.g. GET /persons/1234), whereas RPC tends to use query parameters for function inputs (e.g. GET /readPerson?personid=1234). Not shown in the table is how a REST API would handle filtering, which would typically involve query parameters (e.g. GET /persons?height=tall). Also not shown is how with either system, when you do create/update operations, additional data is probably passed in via the message body (e.g. when you do POST /signup or POST /persons, you include data describing the new person). Of course, none of this is set in stone, but it gives you an idea of what you are likely to encounter and how you might want to organize your own API for consistency. For further discussion of REST URL design, see this question.

因此，我认为:

我的实体是否持有/拥有数据?然后RPC:这是我的一些数据的副本，操作我发送给你的数据副本，并返回给我你的结果的副本。

被调用的实体是否持有/拥有数据?然后REST:要么(1)向我展示你的一些数据的副本，要么(2)操纵你的一些数据。

归根结底，这是关于行为的哪一方拥有/持有数据。是的，您可以使用REST语言与基于RPC的系统进行通信，但是在这样做的时候仍然会执行RPC活动。

示例1:我有一个对象，它通过DAO与关系数据库存储(或任何其他类型的数据存储)通信。对于我的对象和数据访问对象(可以作为API存在)之间的交互，使用REST样式是有意义的。我的实体并不拥有/持有数据，而是关系数据库(或非关系数据存储)拥有。

Example 2: I need to do a lot of complex math. I don't want to load a bunch of math methods into my object, I just want to pass some values to something else that can do all kinds of math, and get a result. Then RPC style makes sense, because the math object/entity will expose to my object a whole bunch of operations. Note that these methods might all be exposed as individual APIs and I might call any of them with GET. I can even claim this is RESTful because I am calling via HTTP GET but really under the covers it is RPC. My entity owns/holds the data, the remote entity is just performing manipulations on the copies of the data that I sent to it.

共享的URL看起来像RPC端点。 下面是RPC和REST的示例。希望这有助于理解什么时候可以使用它们。

让我们考虑一个端点，它向客户发送应用程序维护中断电子邮件。

这个端点执行一个特定的操作。

RPC

POST https://localhost:8080/sendOutageEmails

BODY: {"message": "we have a scheduled system downtime today at 1 AM"}

REST

POST https://localhost:8080/emails/outage

BODY: {"message": "we have a scheduled system downtime today at 1 AM"}

在这种情况下，RPC端点更适合使用。当API调用执行单个任务或操作时，通常使用RPC端点。显然，我们可以使用REST，但端点不是很REST化的，因为我们没有对资源执行操作。

现在让我们看看在数据库中存储一些数据的端点。(典型CRUD操作)

RPC

POST https://localhost:8080/saveBookDetails

BODY: {"id": "123", "name": "book1", "year": "2020"}

REST

POST https://localhost:8080/books

BODY: {"id": "123", "name": "book1", "year": "2020"}

REST对于这种情况(CRUD)要好得多。在这里，读取(GET)或删除(delete)或更新(PUT)可以通过使用适当的HTTP方法来完成。方法决定对资源(在本例中为“books”)的操作。 在这里使用RPC是不合适的，因为我们需要为每个CRUD操作(/getBookDetails， /deleteBookDetails， /updateBookDetails)设置不同的路径，并且必须为应用程序中的所有资源执行此操作。

总而言之,

RPC可用于执行单个特定操作的端点。 资源需要CRUD操作的端点的REST。