A

alias

Alias is a string that's used by Yii to refer to the class or directory such as @app/vendor. Read more in "Aliases".

asset

Asset refers to a resource file. Typically, it contains JavaScript or CSS code but can be any static content accessed via HTTP.

C

configuration

The Configuration may refer either to the process of setting properties of an object or to a configuration file that stores settings for an object, or a class of objects. Read more in "Configuration".

D

DI

Dependency Injection is a programming technique where an object injects a dependent object. "DI"

I

installation

Installation is a process of preparing something to work either by following a readme file or by executing a specially prepared script. In case of Yii, it's setting permissions and fulfilling software requirements.

M

middleware

Middleware is a processor in the request processing stack. Given a request, it may either produce a response or do some action and pass processing to the next middleware. Read more in "Middleware".

module

The module is a sub-application which groups some code based on use-case. It's typically used within the main application and may contain URL handlers or console commands.

N

namespace

Namespace refers to a PHP language feature.

P

package

A package usually refers to Composer package. It's code ready for reuse and redistribution installable automatically via package manager.

R

rule

The rule usually refers to a validation rule of the yiisoft/validator package. It holds a set of parameters for checking if a data set is valid. "Rule handler" does the actual processing.

Q

queue

A queue is similar to a stack. Queue follows First-In-First-Out methodology.

V

vendor

A Vendor is an organization or individual developer providing code in the form of packages. It also may refer to Composer's vendor directory.