Glossary

This glossary explains the terms of the course briefly and links to the chapter that introduces each one. The German pages keep many of these terms in English, such as props, slots, store, router or composable, because that is how you meet them in documentation, error messages and code.

Term	Meaning	Chapter
Accessibility	People can use an app with the keyboard alone, with a screen reader or with strong magnification.	8.5
Action	A function in a store that changes its state, often after a request to the server.	7.2
Adapter	A layer that hides an outside interface such as fetch behind functions of its own, so the implementation can be swapped.	8.2
ADR	An architecture decision record keeps one decision about the architecture in a short file, with its title, status, context, decision and consequences.	8.3
API	The interface an app uses to get data from a server and send data to it. In the course this is the course API, which serves JSON over HTTP.	7.3
async and await	A way of writing asynchronous code so that it reads from top to bottom like ordinary code. await waits until a promise is fulfilled.	1.4
Build	The step in which Vite bundles and minifies the code for publishing. The result ends up in the folder dist.	2.3
Callback	A function you pass to another function so that it can call it later, as with map or an event.	1.3
Closure	A function that keeps access to the variables of the scope it was created in.	1.3
Component	A building block of the interface with its own template, logic and styles.	4.1
Composable	A function that bundles state and logic with the Composition API so that several components can use it. Its name starts with use.	5.4
computed	A value that Vue derives from other reactive values and only recalculates when one of them changes.	3.4
CORS	Cross-origin resource sharing lets a page read data from another origin when the server of that origin allows it. Without that permission the browser blocks the response.	7.3
Deployment	Publishing the built app on a server, in the course on GitHub Pages.	8.6
Directive	An attribute in a template such as v-if, v-for or v-on that tells Vue what to do with an element.	3.3
Environment variable	A value such as the address of the API that Vite reads from files like .env.local. In code it is available under import.meta.env.	2.3
Event	A message from a child component to its parent, raised with emit.	4.3
Event loop	The mechanism that runs waiting tasks such as timers or responses from a server once the call stack is empty.	1.4
Framework	A foundation that takes care of rendering, reactivity and routing for an app, such as Vue, React or Angular.	3.1
Getter	In a store, a derived value like computed in a component. In JavaScript in general, a function that runs when a property is read.	1.5, 7.2
Hash mode	Routing in which the path follows the # sign in the address. The browser never sends that part to the server.	2.2, 6.1
History mode	Routing with ordinary paths such as /items/6. The server has to deliver the app for every such address.	6.1
Hot module replacement	Vite swaps changed parts such as CSS or a Vue component in the running browser without reloading the whole page.	2.3
Lazy loading	The code of a route is only loaded when someone opens it.	6.5
Lifecycle	The phases of a component from creation through mounting to removal. Hooks such as onMounted run in these phases.	5.3
localStorage	Browser storage that keeps text per origin, even after the browser was closed.	7.4
Lock file	A file such as package-lock.json that records the exact versions of every installed package.	1.1
Module	A file with its own scope that shares values with export and takes values from other modules with import.	1.1
MPA	A multi-page application, a website in which every click on a link loads a new HTML page from the server.	2.1
Navigation guard	A function that Vue Router calls during a navigation. A guard that runs before the change can allow it, redirect it or cancel it.	6.4
npm	The package manager of Node.js. It installs packages and runs the scripts in package.json.	1.1
Parameter	A variable part of a path, such as :id in /items/:id.	6.2
Persistence	State survives a reload of the page or a later visit.	7.4
Pinia	The library for stores in Vue.	7.2
Promise	An object for a result that is only known later. A promise is either fulfilled or rejected.	1.4
Props	Values a parent component passes to a child component. The child reads them but doesn't change them.	4.2
Provide and inject	A component makes a value available with provide, and components further down the tree get it with inject.	4.5
Proxy	In JavaScript, an object that intercepts access to another object, the basis of Vue's reactivity. In Vite, a proxy of the dev server forwards requests to another server.	1.5, 2.3
Query	The part of the address after the ? sign, such as ?q=saw, used for search and filters.	6.2
Reactivity	Vue keeps track of which values a template or a computed reads and updates the interface when those values change.	5.1
ref	A reactive container for a value. In the script you read and write it through .value.	3.4
Render function	A function that turns state into HTML. In the course you first write one by hand.	2.2
Route	The mapping of a path to a page of the app.	6.1
Router	The part of the app that reads the address and shows the matching page. In Vue this is Vue Router.	6.1
Server state	Data that belongs to the server and that an app only keeps a copy of, such as the catalog.	7.5
sessionStorage	Browser storage that keeps text only until the tab is closed.	7.4
Single file component	A file ending in .vue that holds the template, script and styles of a component.	3.2
Single page application	A web app that loads once and then changes pages in the browser without fetching new HTML pages from the server.	2.1
Slot	A placeholder in a component that the parent fills with content of its own.	4.4
SSR	In server-side rendering, the server creates the HTML of a page before the browser receives it.	2.1
State	The data an app currently holds and from which it draws the interface.	7.1
Store	Shared state with actions and getters that several components use.	7.2
Teleport	Vue renders part of a component at another place in the DOM, such as a dialog at the end of the page.	4.5
Template	HTML with Vue's syntax, from which Vue creates the interface of a component.	3.3
Template ref	A reference to an element in the template, for example to move the focus. In Vue you get it with useTemplateRef.	5.3
Test	Code that checks whether other code does what it should. In the course you write tests with Vitest and Vue Test Utils.	8.4
v-model	A two-way binding between an input or a component and a value.	3.5, 4.3
Vite	A tool with a dev server and a build for web projects, which create-vue also sets up.	2.3
Watcher	A function that triggers something after a value changes, such as saving or a request. In Vue you write one with watch or watchEffect.	5.2