Generally a "major" version update should be treated as a new version of Java, not just an update. The new naming scheme makes that more clear, IE. you say Java 6 update 30, as in the 30th update of Java 6. Java 7 is NOT an update of Java 6, it is a totally new Java product with its own updating life cycle, its own rules, its own security standards, its own compatibility matrix, its own performance metrics, its own bugs and its own features. Any feature part of Java 7, such as JavaFX 2.1 as a notable example, should not be considered and likely cannot be used in lower release versions.
Ok, I got it now, and only one more thing, the java updates are released with a new end number every month there is a new released of Patches, for example, there is a new Update advisory February 2013, that means that is necessary to have JRE 1.4.2_40 (in this case _40) means it is the lates patch I should download, and for example in January 2013 the latest patch was 1.4.2_39... and proably patches from 2012 where 38... 37.. etc. so each month new vulnerabilites, new patches to applied are all in one big package with a new number at the end of the file? Thanks for your help!!!
Don't make it any more difficult than it has to be. Download the latest version available. Generally Java auto-updates too if you're not running ancient, broken, unsupported and insecure versions (like you are).
Each subsequent update ALWAYS contains all the fixes/changes from the previous update.
For example: 1.4.2_39 is an update to 1.4.2_38, 1.4.2_37, 1.4.2_36 etc
As it has been stated, 1.4.2 has been EOL'd for a long time. The last public release for 1.4 was in Oct 2008
If you need to use 1.5 or 1.6, which continue to have non-public releases that contain bug and vulnerability fixes, you can contact Oracle Sales:
To answer " Anyeone here, that might help me to find out the difference, or JRE 1.3.1_01 is just an old version of V1.4.2_08. Thanks a lot!"
Yes. 1.3.1_01 is very old, and 1.4.2_08 contains all the fixes/features/changes that are in 1.3.1_01. There is considerable change between the two.
You are going to have to do some work to figure out the differences if that is your intention.
Each family release moves the code base forward, containing all the features/fixes from the previous family.
1.4.2 introduced new features, and had many, many fixes. Each 1.4.2 update has release notes that list the changes that you can find and read.