Here is a list of all documented files with brief descriptions:

quasar
core
Application.h	The application: it creates the window, owns the layers and runs the main loop
Base.h	Contains the base definitions and utilities for the Quasar engine
EntryPoint.h	The function that each program built on the engine provides, to create its application
ImGuiLayer.h	The layer that runs Dear ImGui, so that every layer can draw ImGui windows
ImGuiTheme.h	The look of the ImGui interface: colors, spacing and font
Input.h	Functions that read the current state of the keyboard and the mouse
KeyCodes.h	Codes of the keyboard keys, independent from GLFW
Layer.h	Base class for every part of an application that is updated, rendered and receives events
LayerStack.h	Ordered list of the layers of an application, with overlays always above regular layers
Log.h	Engine and application loggers, and the macros to write to them
MemoryLogSink.h	Log sink that keeps the most recent messages in memory, for the console
MouseCodes.h	Codes of the mouse buttons, independent from GLFW
PlatformDetection.h	Detects the platform and the build type at compile time
ScopedTimer.h	Timer that logs how long a scope took when the scope ends
Timer.h	A high-resolution (steady) timer for measuring elapsed time
Timestep.h	Contains the Timestep class, which represents a time duration in seconds
UUID.h	Unique identifier for entities, assets and any object saved in a file
Window.h	Application window, created with GLFW
events
Event.h	Base class of all events, with their types and categories
EventDispatcher.h	Calls the right handler for an event, depending on its type
KeyEvent.h	Events sent by the keyboard: key presses, key releases and typed characters
MouseEvent.h	Events sent by the mouse: cursor moves, scrolling and button presses and releases
WindowEvent.h	Events sent by the window: close, resize, focus changes and minimization
io
File.h	Functions to read and write whole files, and to create directories
Path.h	Functions to convert paths to the form stored in engine files
UserConfigDirectory.h	The folder where the engine stores the settings of the current user
Version.h	Contains the version of the Quasar engine