The other three are also pretty old, probably older than 3,000 years old. Now these four texts are a combination of rituals, of hymns, of mantras, of songs, and of philosophy. For example, Rig Veda, Rig you can translate as meaning praise, so it's knowledge of ways to praise, praise the eternal or praise God. Yajur Veda you could view as these prose mantras, knowledge of these prose mantras is Yajur Veda. Sama Veda, this is knowledge of songs or hymns. Atharva Veda, you can view these as knowledge of things that you should do in your life. Now these four texts can be subclassified into the type of text that they actually are.