 Welcome to module three of this course, which is on the topic of modeling of software modeling and what we'll cover in this is a recap of the UML diagram types So this course assumes that you have already knowledge in that so it's really just a Quick recap of what the different options are in particular one thing that we will discuss because it's often skipped is The UML component diagram, which is a really important diagram for example for architecture descriptions So that's why it's important to look at it. It's quite similar to the class diagrams in many ways But we'll dive into that for shorter time then we discuss What is actually a model because again many courses introduced to different diagrams You can draw and you have to draw a class diagram. You have to do different things But on a theoretical level it might be important to actually discuss what the model is what it should be and especially also what is in other areas of software engineering, but also other disciplines then we get into the context of diagrams Versus models, so what is actually the difference between having a diagram and what is the model Next up we will discuss the purpose of modeling like why should you do this? Again, there are many courses that Tell you to do it, but as very little reflection on what is actually useful. What is the purpose of it? Why should you do it? When should you do it and we go then a bit more into depth on When to model and when to skip Because this course is on software engineering it has a lot to do with managing software products with achieving the right quality and It's really really important There is no clear answer and you need to understand when this comes in handy and otherwise you should skip it You should not just blindly follow the idea of always do this or always do that Everything depends on the context. So these are things we'll cover and Next up we go a bit into the different UML diagram types just a very quick run through what we have