The DOS world's need for memory grew and the 64KB available to .COM executables was no longer adequate. The NE "new executable" executable file format was invented and uses the .EXE file extension rather than .COM. The first 2 bytes of these files includes a tag at the front to identify the format and if you guessed that this was "NE" to denote "new executable", you'd be incorrect. The first 2 bytes of every .EXE file are "MZ" famously because the name of the programmer at Microsoft who wrote the code was "Mark Zbikowski".
RIFF (.wav) file format has been around unchanged since the early 1990s and still in common use today. This goes back to a time when CD audio formats were king and RIFF .wav follows the red book convention pretty closely, with the change that the number of channels, bits per sample and samples per second can vary as described in the file header.
As an example file, I have selected TADA.WAV from Windows 10, \windows\media\tada.wav. This file is 285,228 bytes, the important part is in the first 44 bytes shown here.
When your computer has more than 1 sound card, you may find it cumbersome to change audio devices. The standard method requires going through the control panel or settings application , a process of multiple dialogs and multiple clicks. There is a better way.
My primary desktop computer has an integrated audio device on the system board and a USB attached Blue Yeti microphone. Great mic, it makes me sound good on online meetings and that's a win. The Yeti in addition to being a high quality microphone also has a headphone jack underneath, which has a very high quality DAC and permits great music playback as well as the ability to hear yourself when you talk in online meetings. In my view, that last part is kindof not needed, but it is there and if you mute the microphone, you can listen to music without hearing yourself type. With two audio devices in the machine, Windows allows easy selection of default audio device for playback and default audio device for recording and as you may guess, my configuration is to use the Yeti microphone for recording and the system speakers for playback. Now, add Skype for Business audio conferencing and you'll find that when using the Yeti as microphone, Skype absolutely INSISTS on using the headphone audio connection on the Yeti as audio playback device - a device which normally has nothing plugged in. The result is that when you join meetings, the audience can hear you, but you cannot hear them.
I struggled with this for a bit, using phones to dial into meetings. I have since found the configuration screens to tell Skype to use the system speakers for conferencing.