The type of bar code which you see most often on individual product packs will be one of a set of codes known collectively as '1-dimensional' (or 1-D) bar codes.
The simplest of these is Code 39; some other common types are EAN13, Interleaved 2 of 5, and Code 128.
Some of these will encode only numeric characters; others can encode any character.
But none of them is designed to encode more than a couple of dozen, or so, characters, because this will generate a bar code which is too wide for most scanners to read successfully.
For encoding a larger number of characters (as is implied by your "name age address contact information" requirement), you need to think about using one of the 2-D bar codes.
The most common of these are PDF417 (a 'stacked' code), Data Matrix, and QR Code (both of which are matrix codes).
2-D bar codes, as well as having a much greater capacity than 1-D codes, also include error correction features (1-D bar codes only include error detection).
BUT 2-D bar codes are MUCH more difficult to encode, so you'd probably need to purchase software to do this for you.
And scanners which can read 2-D codes are more expensive too.
Having said that, many modern mobile phones (e.g. Nokia E71) can read Data Matrix and QR Codes, provided that the symbols are not too large (in terms of encoded data capacity).
These phones should be able to read 2-D bar codes which encode up to 150 or so data characters, but would struggle with the larger symbols encoding hundreds (or even thousands) of characters.