In this talk, I will try to motivate a construction towards Fontaine's ring of de Rham periods. Then I will state some p-adic Hodge comparison results obtained in the 90s by many profound mathematicians. In the unlikely event of having some remaining minutes, I will try to wrap up by stating a small open problem (tangentially) related to these thingamabobs. Speaker(s): Shizhang Li (University of Michigan)