M4P (MPEG-4 Protected) is a digital audio file extension for the AAC (Advanced Audio Codec) container format. It uses lossy compression and is an audio-only file. In most cases, M4P files are purchased on Apple iTunes, which means they are DRM-protected. M4A is the unprotected version of M4P.
MKA is a free Matroska Multimedia Container format that can store multiple audio, video, image, and subtitle tracks. It’s used to save typical multimedia content such as TV shows and movies and comes with a .mkv for video files. When used on audio files, it features a .mka filename extension, .mks for subtitles, and .mk3d for stereoscopic video files.