Serialization is the process of turning some object into a data format that can be restored later. People often serialize objects in order to save them to storage, or to send as part of communications. Deserialization is the reverse of that process -- taking data structured from some format, and rebuilding it into an object - OWASP

Check the following sub-sections, located in other files :

Java deserialization : ysoserial, ...
PHP (Object injection) : phpggc, ...
Ruby : universal rce gadget, ...
Python : pickle, ...

References

Github - ysoserial
Java-Deserialization-Cheat-Sheet - GrrrDog
Understanding & practicing java deserialization exploits
How i found a 1500$ worth Deserialization vulnerability - @D0rkerDevil
Misconfigured JSF ViewStates can lead to severe RCE vulnerabilities - 14 Aug 2017, Peter Stöckli
PHP Object Injection - OWASP
PHP Object Injection - Thin Ba Shane
PHP unserialize
PHP Generic Gadget - ambionics security
RUBY 2.X UNIVERSAL RCE DESERIALIZATION GADGET CHAIN - elttam, Luke Jahnke
Java Deserialization in manager.paypal.com by Michael Stepankin
Instagram's Million Dollar Bug by Wesley Wineberg
(Ruby Cookie Deserialization RCE on facebooksearch.algolia.com by Michiel Prins (michiel)
Java deserialization by meals