Clarify some descriptions regarding resource cache

doc/classes/Resource.xml

@@ -4,8 +4,9 @@
 		Base class for serializable objects.
 	</brief_description>
 	<description>
-		Resource is the base class for all Godot-specific resource types, serving primarily as data containers. Since they inherit from [RefCounted], resources are reference-counted and freed when no longer in use. They can also be nested within other resources, and saved on disk. Once loaded from disk, further attempts to load a resource by [member resource_path] returns the same reference. [PackedScene], one of the most common [Object]s in a Godot project, is also a resource, uniquely capable of storing and instantiating the [Node]s it contains as many times as desired.
+		Resource is the base class for all Godot-specific resource types, serving primarily as data containers. Since they inherit from [RefCounted], resources are reference-counted and freed when no longer in use. They can also be nested within other resources, and saved on disk. [PackedScene], one of the most common [Object]s in a Godot project, is also a resource, uniquely capable of storing and instantiating the [Node]s it contains as many times as desired.
 		In GDScript, resources can loaded from disk by their [member resource_path] using [method @GDScript.load] or [method @GDScript.preload].
+		The engine keeps a global cache of all loaded resources, referenced by paths (see [method ResourceLoader.has_cached]). A resource will be cached when loaded for the first time and removed from cache once all references are released. When a resource is cached, subsequent loads using its path will return the cached reference.
 		[b]Note:[/b] In C#, resources will not be freed instantly after they are no longer in use. Instead, garbage collection will run periodically and will free resources that are no longer in use. This means that unused resources will linger on for a while before being removed.
 	</description>
 	<tutorials>

doc/classes/ResourceLoader.xml

@@ -28,6 +28,7 @@
 			<description>
 				Returns whether a recognized resource exists for the given [param path].
 				An optional [param type_hint] can be used to further specify the [Resource] type that should be handled by the [ResourceFormatLoader]. Anything that inherits from [Resource] can be used as a type hint, for example [Image].
+				[b]Note:[/b] If you use [method Resource.take_over_path], this method will return [code]true[/code] for the taken path even if the resource wasn't saved (i.e. exists only in resource cache).
 			</description>
 		</method>
 		<method name="get_dependencies">
@@ -137,10 +138,13 @@
 			The resource was loaded successfully and can be accessed via [method load_threaded_get].
 		</constant>
 		<constant name="CACHE_MODE_IGNORE" value="0" enum="CacheMode">
+			The resource is always loaded from disk, even if a cache entry exists for its path, and the newly loaded copy will not be cached. Instances loaded with this mode will exist independently.
 		</constant>
 		<constant name="CACHE_MODE_REUSE" value="1" enum="CacheMode">
+			If a resource is cached, returns the cached reference. Otherwise it's loaded from disk.
 		</constant>
 		<constant name="CACHE_MODE_REPLACE" value="2" enum="CacheMode">
+			The resource is always loaded from disk, even if a cache entry exists for its path. The cached entry will be replaced by the newly loaded copy.
 		</constant>
 	</constants>
 </class>

modules/gdscript/doc_classes/@GDScript.xml

@@ -162,7 +162,7 @@
 			<return type="Resource" />
 			<param index="0" name="path" type="String" />
 			<description>
-				Returns a [Resource] from the filesystem located at the absolute [param path]. Unless it's already referenced elsewhere (such as in another script or in the scene), the resource is loaded from disk on function call, which might cause a slight delay, especially when loading large scenes. To avoid unnecessary delays when loading something multiple times, either store the resource in a variable or use [method preload].
+				Returns a [Resource] from the filesystem located at the absolute [param path]. Unless it's already referenced elsewhere (such as in another script or in the scene), the resource is loaded from disk on function call, which might cause a slight delay, especially when loading large scenes. To avoid unnecessary delays when loading something multiple times, either store the resource in a variable or use [method preload]. This method is equivalent of using [method ResourceLoader.load] with [constant ResourceLoader.CACHE_MODE_REUSE].
 				[b]Note:[/b] Resource paths can be obtained by right-clicking on a resource in the FileSystem dock and choosing "Copy Path", or by dragging the file from the FileSystem dock into the current script.
 				[codeblock]
 				# Load a scene called "main" located in the root of the project directory and cache it in a variable.