I'm trying to wrap my head around how MT and MD options are used when compiling C/C++ projects. However, without being able to expand these supposed abbreviations to meaningful phrases, I forget which one is which from one paragraph to the next. Strangely enough none of the text I've read starts by defining the M, the T and the D. What do they stand for?

我正在试图理解编译C/C++项目时如何使用MT和MD选项。然而，由于无法将这些假定的缩略语扩展为有意义的短语，我忘记了从一段到下一段哪个是哪个。奇怪的是，我读过的文章都不是从定义M、T和D开始的，它们代表什么？

From the compiler options link given by chris above:

从Chris上面给出的编译器选项链接：

https://learn.microsoft.com/en-us/cpp/build/reference/compiler-options-listed-alphabetically?view=vs-2019

Https://learn.microsoft.com/en-us/cpp/build/reference/compiler-options-listed-alphabetically?view=vs-2019

/MD    Creates a multithreaded DLL using MSVCRT.lib.
/MDd   Creates a debug multithreaded DLL using MSVCRTD.lib.
/MT    Creates a multithreaded executable file using LIBCMT.lib.
/MTd   Creates a debug multithreaded executable file using LIBCMTD.lib.

Thus MT stands for Multithreaded and MD stands for Multithreaded DLL.

因此，MT代表多线程，MD代表多线程DLL。

These switches for cl.exe specify which C runtime library to link against; /MT specifies to link with LIBCMT.LIB; /MD specifies to link with MSVCRT.LIB.

Cl.exe的这些开关指定要链接到哪个C运行时库；/MT指定链接到LIBCMT.LIB；/MD指定链接到MSVCRT.LIB。

The different CRT libraries are described in greater detail here. The primary difference between LIBCMT and MSVCRT is that the former links the CRT statically into your output file, whereas MSVCRT links to the VC runtime DLL (which, unlike its name suggests, is not MSVCRT.DLL (see here)).

这里更详细地描述了不同的CRT库。LIBCMT和MSVCRT之间的主要区别是前者将CRT静态链接到您的输出文件，而MSVCRT链接到VC运行时DLL(与其名称不同，它不是MSVCRT.DLL(参见此处))。

DLL and internal may be used as mnemonic to distinguish /MD from /MT.

DLL和internal可以用作助记符来区分/MD和/MT。

I also searched this for my question, and here are more detailed explanations by MSDN:

我也在上面搜索了我的问题，以下是MSDN更详细的解释：

MSVC compiler options

MSVC编译器选项

(emphasis mine)

(重点是我的)

/MD Causes the application to use the multithread-specific and
DLL-specific version of the run-time library. Defines _MT and _DLL and
causes the compiler to place the library name MSVCRT.lib into the .obj
file.

Applications compiled with this option are statically linked to
MSVCRT.lib. This library provides a layer of code that enables the
linker to resolve external references. The actual working code is
contained in MSVCRversionnumber.DLL, which must be available at run
time to applications linked with MSVCRT.lib.

/MDd Defines _DEBUG, _MT, and _DLL and causes the application to use
the debug multithread-specific and DLL-specific version of the
run-time library. It also causes the compiler to place the library
name MSVCRTD.lib into the .obj file.

/MT Causes the application to use the multithread, static version of
the run-time library. Defines _MT and causes the compiler to place the
library name LIBCMT.lib into the .obj file so that the linker will use
LIBCMT.lib to resolve external symbols.

/MTd Defines _DEBUG and _MT. This option also causes the compiler to
place the library name LIBCMTD.lib into the .obj file so that the
linker will use LIBCMTD.lib to resolve external symbols.

The page also explains other compiler options /LD and /LDd, which are used when creating DLLs.

该页面还解释了创建DLL时使用的其他编译器选项/LD和/LDD。