✅ Install VLC for Android from Google Play Store – it plays Xvid, DivX, MKV, AVI, etc., out of the box.
A "codec" (compressor-decompressor) is software that encodes and decodes digital video. If an Android phone encountered a video file compressed with Xvid but lacked the codec, the user would experience errors like "Video cannot be played" or audio playback without video.