Why is MKV better than AVI?

A movie is a combination of video and audio streams. As audio and video can be comfortably played in a single file, both are combined into a single pack format called container. This container format is made to play audio/video files. The popular container formats that can hold audio/video files are ZIP and RAR. The other old container formats are that of AVI like .mpg, .mpeg, .mov, .rm and MP4.
The more advanced file format than all the AVI formats mentioned above is Matroska or MKV format. The available open source alternative is MKV format that has special features. The audio/video container format offered by Microsoft in 1990s was AVI format. AVI constitutes the multimedia software called ‘video for windows,. This software not only provides framework for audio/video container but also contains commands of API, which can be used to prepare new codecs. The new audio/video codecs can be made using VFW or ACM interface.
The ‘video for windows’ or VFW framework do not support some of the advanced features which are offered by some of the modern audio and video compression formats. The advanced features are Variable Bitrate audio encoding (VBR) or Variable Frame rate video encoding (VFR). AVI was improved a little by an additional standard called ‘Open DML AVI’. This additional feature could overcome limitation of 2GB file size. Even though AVI format is developed a little more, it could not reach the standards of modern compression format like open source Ogg Vorbis audio compression format.
Matroska is designed in such a way that it can overcome lot of limitations and can support audio and video compression formats. Matroska tends to reach future standards which is made based on foundation software called EBML. EBML gives the chance to add some more features to the container format keeping intact its previous compatibility with previous files and software. So, MKV is said to be better than AVI as it possesses additional features.