There are seven common actions that Rails expects to be executed on a type of web resource:

• index: list the resources of the type
• make a new resource, that is:
  • new: seek input from the user about the new resource
  • create: add the new resource using that input
• work with a specific resource, in one of a few ways:
  • show: show it
  • destroy: delete it
  • change it, that is:
    • edit: seek input from the user about the change
    • update: update the resource using that input

These seven actions correspond to different routes that Rails’ resources controller helper function will set up. In learning these, I found it helpful to look at the relationships involved from a few different angles. Personally, things made the most sense when organized around the different HTTP verbs being used.

HTTP Verbs

HTTP Verb	Action	Path
GET	index	/photos
	show	/photos/:id
	new	/photos/new
	edit	/photos/:id/edit
POST	create	/photos
PATCH/PUT	update	/photos/:id
DELETE	destroy	/photos/:id

Routes

Path	HTTP Verb	Action
/photos	GET	index
	POST	create
/photos/new	GET	new
/photos/:id	GET	show
	PATCH/PUT	update
	DELETE	destroy
/photos/:id/edit	GET	edit

Actions

Action	Path	HTTP Verb
index	/photos	GET
new	/photos/new	GET
create	/photos	POST
show	/photos/:id	GET
destroy	/photos/:id	DELETE
edit	/photos/:id/edit	GET
update	/photos/:id	PATCH/PUT

CRUD

Another angle on this is to consider the four CRUD actions - Create, Read, Update, and Destroy:

Action	Path	HTTP Verb
Create
new	/photos/new	GET
create	/photos	POST
Read
index	/photos	GET
show	/photos/:id	GET
Update
edit	/photos/:id/edit	GET
update	/photos/:id	PATCH/PUT
Destroy
destroy	/photos/:id	DELETE