Clarify basics documentation page

Author: mrexodia

docs/basics.md

@@ -16,23 +16,36 @@ A CMake **project** is a collection of targets. In the context of libraries the
 
 ## Targets
 
-The basic unit of CMake is called a **target**. A target (also referred to as [binary target](https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#binary-targets) in the CMake documentation) corresponds to an executable or library you can build. There are also [pseudo targets](https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#pseudo-targets), but we ignore them for now.
+The basic unit of CMake is called a **target**. A target (also referred to as [binary target](https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#binary-targets) in the CMake documentation) corresponds to an executable or static/dynamic library you can build. There are also [pseudo targets](https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html#pseudo-targets), but we ignore them for now.
 
 <sub>Visual Studio: a **target** corresponds to a _project_.</sub>
 
+Target types:
+
+|Type|Purpose|
+|-|-|
+|Executable|Program you run on your computer (`.exe`)|
+|Static library|Library code _compiled into_ the final executable (`.lib`, `.a`)|
+|Dynamic library|Library code loaded at runtime (`.dll`, `.so`, `.dylib`)|
+|Interface|Used for organizational purposes (common flags/includes/libraries)|
+
 ## Target Properties
 
 Targets have a collection of **properties** that describe how to build them.
 
-Examples of properties:
+The most commonly-used properties:
 
-- _Sources_: the `*.cpp` files used to build the target.
-- _Compile options_: Command line flags for the compiler.
-- _Link libraries_: The **dependencies** required to build this target.
+- [_Sources_](https://cmake.org/cmake/help/latest/command/target_sources.html): the `*.cpp` files used to build the target.
+- [_Include directories_](https://cmake.org/cmake/help/latest/command/target_include_directories.html): Paths to directories the compiler will search when doing `#include`.
+- [_Compile definitions_](https://cmake.org/cmake/help/latest/command/target_compile_definitions.html): Preprocessor macro definitions used for compilation (`-DMYOPTION`).
+- [_Compile options_](https://cmake.org/cmake/help/latest/command/target_compile_options.html): Command line flags for the compiler (platform/compiler specific).
+- [_Compile features_](https://cmake.org/cmake/help/latest/command/target_compile_features.html): C/C++ standard version to build with.
+- [_Link libraries_](https://cmake.org/cmake/help/latest/command/target_link_libraries.html): The **dependencies** required to build this target.
+- [_Link options_](https://cmake.org/cmake/help/latest/command/target_link_options.html): Command line flags for the linker (platform/linker specific).
 
 <sub>See the [CMake documentation](https://cmake.org/cmake/help/latest/manual/cmake-properties.7.html#properties-on-targets) for an exhaustive list of target properties.</sub>
 
-**Important**: The term **link** has a slightly different meaning in CMake than you might expect. In addition to adding a library to the command line of the linker, CMake also propagates properties of the target you link to.
+**Important**: The term **link** has a slightly different meaning in CMake than you might expect. In addition to adding a library to the command line of the linker, CMake also (transitively) propagates properties of the target you link to based on their _visibility_.
 
 <sub>You can think of **linking** as _depending on_.</sub>
 
@@ -44,7 +57,7 @@ The propagation of properties depends on their **visibility**:
 
 In practice you default to **private**, unless consumers of your library _require_ the property to build their target. In that case you use **public**.
 
-### Example
+## Example
 
 The most intuitive example is with _include directories_. Imagine there are two targets:
 
@@ -67,10 +80,39 @@ name = "DataProcessor"
 type = "static"
 sources = ["StringUtils/src/stringutils.cpp"]
 headers = ["StringUtils/include/stringutils.hpp"]
-include-directories = ["StringUtils/include"]
+include-directories = ["StringUtils/include"] # public (default for libraries)
 
 [target.DataProcessor]
 type = "executable"
 sources = ["DataProcessor/src/main.cpp"]
-link-libraries = ["StringUtils"]
-```
+link-libraries = ["StringUtils"] # private (default for executables)
+```
+
+The generated `CMakeLists.txt` (simplified) looks like this:
+
+```cmake
+project(DataProcessor)
+
+# Target: StringUtils
+add_library(StringUtils STATIC
+    "StringUtils/include/stringutils.hpp"
+    "StringUtils/src/stringutils.cpp"
+)
+
+target_sources(StringUtils PRIVATE ${StringUtils_SOURCES})
+
+target_include_directories(StringUtils PUBLIC
+	"StringUtils/include"
+)
+
+# Target: DataProcessor
+add_executable(DataProcessor
+    "DataProcessor/src/main.cpp"
+)
+
+target_sources(DataProcessor PRIVATE ${DataProcessor_SOURCES})
+
+target_link_libraries(DataProcessor PRIVATE
+    StringUtils
+)
+```