Understanding php “Out of memory” error

Question

I can find lots of tutorials on how to overcome the out-of-memory error. The solution is: To increase the memory in the php.ini or in the .htaccess

Answer 1

I Always interpreted it like:

Fatal error: Out of memory ([currently] allocated 32016932) (tried to allocate [additional] 25152 bytes)

But good Question if there is a bulletproof explanation.