GNOME Core Applications

The GNOME Core Applications are a software suite that is packaged with GNOME, a free and open-source desktop environment. The suite provides a consistent look and feel to the GNOME desktop, utilizes the Adwaita design language and tightly integrates with the GNOME desktop. The suite is developed and maintained through GNOME's official GitLab instance.
A comprehensive list of these applications is available at

WWW Official Site

Configuration

Settings – main interface to configure various aspects of GNOME. Diverse panels represent graphical front-ends to configure the NetworkManager daemon and other daemons.

Communication

Contacts – the contacts book app

Files

Document Scanner - Application for operating printer scanners.
Image Viewer (Loupe) – Image viewer.
Document Viewer – Viewer for digital documents such as PDF files.
Files (Nautilus) – File manager.
Audio Player - General purpose audio player.
Video Player – Video player.

System

Connections - the front-end for remote desktops. Introduced in GNOME 41.
Disks - formatting and managing partitions
Disk Usage Analyzer (Baobab) - Used for representing disk usage graphically
Extensions - extension manager for the GNOME desktop
Fonts - the font viewer
Logs – written in Vala, introduced with 3.12
Help (Yelp) - the help documentation software
Software - the software manager, supports native package managers, as well as Flatpaks
System Monitor - shows CPU usage graphs
Terminal Emulators
* Console
* Terminal
* Ptyxis
Web (Epiphany) - the web browser

World

GNOME Clocks - creating alarms and timers
GNOME Maps - map application, powered by OpenStreetMap
Weather - the weather app

Utilities

Development tools

Boxes - the virtualization software
Builder - the IDE for creating GNOME apps
D-Spy - D-Bus analyzer
Dconf Editor - Dconf database editor
Devhelp - API documentation viewer
Sysprof - debugging software

GNOME Circle

is a collection of applications which have been built to extend the GNOME platform, utilize GNOME technologies, and follow the GNOME human interface guidelines. They are hosted, developed, and managed in the GNOME official development infrastructure, on . Developers who are using the GNOME platform can apply for inclusion in GNOME Circle. Benefits include promotional support and eligibility for project contributors to become GNOME Foundation members. Circle applications are not part of GNOME Core Applications.
Some examples of such applications include:

Apostrophe - a markdown editor
Authenticator - a two-factor authentication code generator
Eyedropper - a color picker and formatter utility
Foliate - An ebook reader
Fragments - a torrent manager
Gaphor - UML and SysML modeling tool
Health - a fitness tracker
Pika Backup - a backup software
Polari - messaging app
Wike - a Wikipedia browser