So, we will be talking a lot about UX in this course. We should start simply by defining the term. This is something Mike already touched upon in the first two courses of this specialization, but it's always good to review such fundamental concepts. So, let's get started. Of course, UX stands for user experience, but what does that actually mean? Here's one way to define it. The experience a product or service creates for people in the real world. That's a pretty concise definition, just one sentence, but let's dig a little deeper. What are the words here that stand out? I would say the following three: experience, people, real world. Let's talk about each of these briefly. What happens when we have an experience? It leaves an impression on us, some feeling and often a memory. An experience is usually also accompanied with a qualifying adjective. You could say you had an amazing experience or a horrible experience or the experience could be boring or delightful or charming or confusing or frustrating. I think most of you can remember interacting with a website or an app that could be described in these kinds of terms. Next, there is the word people. So, this is about humans. That's something that one should always remember as a designer, that your creations will affect the lives of actual people. Wouldn't you rather that your work helps and delights them than annoy and frustrate them? Lastly, there's real world. This is to emphasize that we're not talking about theoretical experiences or abstract people, your work has real-world consequences. If your user experience is positive, the website's or your app's goals are much more likely to be fulfilled. Your users will be happy and more likely to buy something or sign up or spend time on your site. They're also more likely to return. Now, here's another thing I want to emphasize. There's a term that often seems to stick to UX like some sort of inseparable partner. I'm talking about UI which stands of course for user interface. You hear about UI, UX as a pair a lot. Most job descriptions ask for UI, UX skills, the specialization is titled UI, UX. It often seems like there isn't even a difference between the terms but that's actually not the case. The author Golden Krishna has a really great way of talking about the difference between UI and UX. Golden wrote a book called, "The Best Interface is No Interface." It's actually an inspiring book and I would recommend you all read it. Here's a page from the book, and here's what golden identifies as UI concerns, navigation, sub-navigation, dropdowns, buttons, links, windows, rounded corners, shadowing, error messages, alerts, updates, checkboxes, and so on. Then, a list of what belongs under UX, people, happiness, solving problems, understanding needs, love, efficiency, entertainment, pleasure, delight, smiles, soul, etc. There's quite a difference between these lists, right? Of course, it's important to design effective navigation menus and beautiful buttons and the decision whether to use rounded corners or not or exactly which shade of color to use can have significant implications, but it's most important to remember why we are designing in the first place. To remember that in the end our work will affect the lives of people. So, you can think about user interface design as part of the greater user experience design universe. I would argue that UI as the visual manifestation of UX thinking. It's important to understand that there are many other concerns that have to be considered to design an effective and successful user experience. Many of these concerns will also be part of this course.