DEVELOPER GLOSSARY

A set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps.

A browser security mechanism that uses HTTP headers to tell browsers to give a web application running at one origin access to selected resources from a different origin.

A workflow pipeline that automates the integration of code changes (testing, linting) and the automated deployment of verified changes to servers.

An attack that forces an authenticated user to execute unwanted actions on a web application in which they're currently authenticated.

A geographically distributed group of servers that work together to provide fast delivery of Internet content like HTML, JS, CSS, and images.

The phonebook of the Internet. It translates human-readable domain names (like google.com) to machine-readable IP addresses (like 142.250.190.46).

An open-source platform that enables developers to package, ship, and run applications in isolated environments called containers.

A programming interface for web documents. It represents the page so that programs can change the document structure, style, and content.

An architectural pattern in which changes to the application state are stored as a sequence of events, rather than just updating the current state in-place.

A query language for APIs and a runtime for fulfilling those queries with your existing data. It allows clients to request exactly what they need.

A high-performance RPC framework developed by Google that uses HTTP/2 for transport and Protocol Buffers as the interface description language.

An open standard that defines a compact and self-contained way for securely transmitting information between parties as a JSON object, signed cryptographically.

An open-source container orchestration system for automating software deployment, scaling, and management.

An architectural style that structures an application as a collection of small, autonomous, loosely coupled services that communicate over APIs.

An industry-standard protocol for authorization that enables applications to obtain limited access to user accounts on an HTTP service, like Google or GitHub.

An architectural style for designing networked applications. It relies on a stateless, client-server communication protocol, almost always HTTP.

A mnemonic acronym for five design principles intended to make software designs more understandable, flexible, and maintainable.

SQL databases are relational, table-based, schema-driven, and scale vertically. NoSQL databases are non-relational, document/key-value based, dynamic-schema, and scale horizontally.

The ability of a web application to render the HTML markup on the server instead of rendering it in the browser's client-side runtime.

A web application rendering pages directly in the browser's DOM using client-side JavaScript. The server sends a bare-bones HTML page with JS bundles.

A communications protocol providing full-duplex communication channels over a single TCP connection, allowing real-time client-server communication.

A client-side process where JavaScript loads in the browser, attaches event listeners to pre-rendered HTML supplied by the server, making it interactive.

An optimization technique that limits the rate at which a function gets triggered by delaying execution until a certain amount of idle time has elapsed.

An optimization technique that limits the maximum number of times a function can be called over a given time interval.

An optimization technique used primarily to speed up computer programs by storing the results of expensive function calls and returning the cached result.

The process of distributing network traffic across multiple servers to ensure no single server bears too much load, improving availability.

The property of certain operations in mathematics and computer science whereby they can be applied multiple times without changing the result.

A security vulnerability where an attacker manipulates SQL queries by injecting malicious SQL statements into entry fields.

A security vulnerability where an attacker injects malicious client-side scripts into web pages viewed by other users.

A network traffic management strategy that limits the number of requests a user or IP address can make to an API within a specific timeframe.

A term commonly used in the JavaScript context for dead-code elimination. It relies on the static structure of ES2015 module syntax (import and export) to discard unused code during bundle compilation.

A suite of different technologies allowing you to create reusable custom elements—with their functionality encapsulated away from the rest of your code—and utilize them in your web apps.

The mechanism that allows JavaScript to perform non-blocking I/O operations, despite being single-threaded, by offloading operations to the system kernel whenever possible.

Functions executed on the server side but triggered from the client-side component directly without declaring dedicated REST endpoints.

A web standard that allows developers to attach a hidden, encapsulated DOM subtree to an element, keeping CSS styling and JavaScript isolated from the main document.

An initiative by Google to provide unified guidance for quality signals that are essential to delivering a great user experience on the web (LCP, FID, CLS).

The algorithm used by browsers to determine which CSS rule gets applied to an element when multiple rules conflict. It is calculated based on selector weight.

The sequence of steps the browser goes through to convert HTML, CSS, and JavaScript into actual pixels on the screen.

A web application that interacts with the user by dynamically rewriting the current web page with new data from the web server, instead of loading entire new pages.

A traditional web application structure where every navigational transition triggers the browser to request and download a new HTML page from the server.

A theorem stating that a distributed data store can simultaneously provide at most two of three guarantees: Consistency, Availability, and Partition Tolerance.

A type of database partitioning that separates very large databases into smaller, faster, more easily managed parts, called data shards, spread across nodes.

A data structure technique (usually using B-Trees) that improves the speed of data retrieval operations on a database table at the cost of slower writes.

A cache of database connections maintained so that connections can be reused when future requests to the database are required.

A family of techniques for providing atomicity and durability in database systems. Changes are written to a secure log file before being applied to the DB pages.

A consistency model used in distributed computing where data updates eventually propagate to all nodes, guaranteeing they match given no new updates.

The frequent copying of data from a primary database on one server to replicas on other servers to create backups or balance read traffic.

An asynchronous service-to-service communication protocol used in serverless and microservices architectures to buffer and route message payloads.

A method of altering the behavior of a web page or application with custom callbacks. They are triggered by events and push payloads via HTTP.

A web development technique where the client requests information from the server and the server holds the request open until new data is available.

A server push technology enabling a client to receive automatic, real-time updates from a server over an HTTP connection, in one direction.

An API management tool that sits between a client and a collection of backend services, acting as a single entry point and reverse proxy.

A programming technique for converting data between incompatible type systems in databases and object-oriented programming languages.

A software design pattern commonly used for developing user interfaces that divides the program logic into three interconnected elements.

The process of managing and provisioning computer data centers through machine-readable definition files, rather than physical configuration.

A workflow pattern that uses Git repositories as the single source of truth for infrastructure and application configurations, automating sync.

A deployment strategy that reduces downtime and risk by running two identical production environments, only one of which is live at any time.

A deployment strategy where a new version of software is rolled out to a small subset of users before making it available to the entire userbase.

A cloud-computing execution model where the cloud provider acts as the server, dynamically managing the allocation and scaling of machine resources.

A deployment pipeline setup where servers are updated to a new version without interrupting active client requests or closing service sockets.

A security practice for storing passwords. A salt (random string) is appended to the password, which is then run through a one-way hashing algorithm.

An extension of HTTP that uses TLS (formerly SSL) to encrypt all communications between a client's browser and the web server, securing data in transit.

An HTTP header that allows site operators to restrict the resources (such as JavaScript, CSS, Images) that the browser is allowed to load for a given page.

A malicious attempt to disrupt normal traffic of a targeted server, service, or network by overwhelming the target with a flood of Internet traffic.

The practice of limiting access rights for users, applications, and system processes to only those permissions absolutely necessary to perform their work.

An identity verification layer built on top of the OAuth 2.0 protocol, allowing clients to verify the identity of the end-user using tokens.

A principle of software development aimed at reducing repetition of software patterns, replacing it with abstractions or data normalization.

A principle of extreme programming that states a programmer should not add functionality until deemed absolutely necessary.

A design principle stating that systems work best if they are kept simple rather than made complicated; unnecessary complexity should be avoided.

A software architecture model where the user interface, backend application database accesses, and workers are packaged in a single, unified program.

A dedicated infrastructure layer built into an application to control service-to-service communications, managing security, routing, and logging.

A system design quality that ensures a pre-agreed level of operational performance (usually uptime) is maintained during a given period.

The property that enables a system to continue operating properly in the event of the failure of one or more of its internal components.

A widely adopted versioning system for software releases defined as: MAJOR version for breaking API changes, MINOR version for backwards-compatible features, and PATCH for backwards-compatible bug fixes.

A flaw in an electronic or software system where the output is dependent on the sequence or timing of uncontrollable concurrent events.