@nitinkhanna This from Wikipedia: QuickTime is an extensible multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity.
QuickTime X is the version which was released in 2009 with Snow Leopard (OS X 10.6). Users no longer had to buy & activate the Pro features of QuickTime 7 in order to edit media.
Most users quickly discovered that the X version was greatly lacking in the number & variety of export formats. Fortunately it's possible to install both QT 7 & QT X provided the former is not in the Applications folder (otherwise it gets over-ridden by QT updates). My copy of QT 7 Pro resides in the Utilities subfolder in the Applications folder.
An alternative location is the Applications folder in the user's home folder.
// @jextxadore