Understanding Diagrams [closed]

Solution 1:

1 Yes it is UML. You can read more (with examples) about class diagrams and other UML diagrams e.g. at http://www.uml-diagrams.org/class-diagrams-overview.html

2 Although it is possible to Google out and print and pin up on your notice board some "UML cheat sheet" or "UML quick reference card" (e.g. http://www.holub.com/goodies/uml).

3 it is much better to first read a good book so that you know what is/is_not possible what is the structural/behavioral modeling etc. Explaining UML is not a thing that can be done on 1 single sheet of paper or in one single Stack Overflow answer

Solution 2:

Here is a key that I found here

***EDIT @xmojmr's request, here is an updated diagram that I found here (detailed definitions can be found in the linked page):