system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How, and why do operating systems, and software become outdated?
gpt
Software becomes outdated when:

* it lacks features that have become commonplace
* it relies on features in hardware or other software that are no longer being provided

For example, an application might run in 32 bit mode only.  A new OS might decide they are no longer supporting 32 bit mode, and require all software to run in 64 bit mode.  That software is now outdated.

Or can be more subtle.  A website written in raw HTML without frames or style sheets or javascript might work just fine, but it will look old fashioned and outdated.

Often when software becomes too outdated, the vendor will stop supporting it.  If you find a bug, they will no longer fix it or help you work around it, instead they will tell you to upgrade.