[MUSIC] It's very important to understand the difference between an audio file and audio clip. You need to know what audio clips are and how you might use them. So audio clips, they're not actual files. Audio clips are references to existing files. So this is very useful, because if you're editing, or applying effects to an actual file, you might find that you do damage to that file, that you destructively edit it. Audio clips prevent this. What they do is they allow you to make very different, or any number of different versions of an audio clip which relates to an existing audio file. So you're file's here, and it stays there, it's untouched, unedited. And you can have a series of clips that might reference different things, different parts of your audio file, and allow you to apply effects. This is a standard method of non-linear digital editing. Usually we refer to these things as regions. In unity, they're described as audio clips. It means you can make changes specifically to different audio clips at run time. And this is great, because audio clips can be defined to load into memory in different ways, either to be streamed from disk, or to be present in RAM. As I've previously already explained to you, this is useful for increasing the reliability of your performance when you're adding audio. You can say a particular audio clip is useful, or a fragment of an audio clip is useful, to be loaded into RAM, to be used as a sound effect. But another aspect of a sound file might be a different, separate clip, and that might be loaded in a different way. So this is quite a powerful feature of Unity that affects both how you choose to select and list all of the different audio components you're using, but also how you decide how they're loaded when you start up your virtual environment. One thing that I feel is really important to reinforce is about your awareness of when you're using compressed audio. Now, this is because Unity's default mode is compressed audio. If you're importing audio and using it in Unity, it's going to compress it, and you're not going to know. If its compressing it into mp3 format and you've spent time and money generating really high quality music and sound effects, you're really causing damage to your pocket, okay? Now, I'm not the only person who thinks this. This is not my prejudice. Mp3 and other forms of compressed audio really impact on the user experience. And you need to be careful. It can be fine for things like sound beds and for some music, it can be absolutely fine. But it's very important that you at least understand whether the sounds you're using are uncompressed or not. You don't want to degrade the audio quality. Also, there is another feature of compressed audio. Compressed audio, it's going to take longer for the machine to process, which means its going to slow everything down. The computer has to spend time uncompressing it in order to play it in real time. This is another reason why I keep saying if you're doing fast sound effects, let's imagine that yeah, the gun is the classic example, or knocking on a table, or any kind of real time interactive audio effect, you really want to consider using a uncompressed sound. Also, audio clips, they can be edited directly from scripts. So this is a really powerful feature, and you should remember from what I've already explained, the audio file itself is just a list of numbers. If you've got uncompressed audio sitting in a file, it's much easier to do signal processing on it, and it will happen much more quickly and it will be dynamic in memory. [MUSIC]