Space and Time

AWS can be very cheap or very expensive depending on how you use it. 0:00 To understand pricing on AWS, 0:05 we need to talk about two related concepts, space and time. 0:07 Space is a measure of capacity or capability. 0:11 For example, a computer with a large hard drive is capable of holding a lot of 0:14 information, so we say it has a lot of space. 0:18 But storage capacity isn't the only kind of capacity there is. 0:21 What about processor capacity? 0:24 A computer with a fast processor is capable of processing a lot of 0:27 information. 0:30 So we also say it has a lot of space, even if it has a small hard drive. 0:31 There's also network capacity, 0:36 which is how fast the computer is able to talk to other computers. 0:37 We could say that a computer with a very fast network has a lot of space. 0:41 Basically, you can think of space as a measure of how powerful a computer is. 0:45 More powerful computers are capable of holding more stuff and doing more stuff. 0:50 Then there's time. 0:55 Time is a pretty straightforward concept. 0:56 It's a measure of how long it takes to do something, but things get a bit 0:58 more complicated when you have multiple actors working simultaneously. 1:02 Let's say you need to stuff 60 envelopes and 1:06 it takes a minute to stuff one envelope. 1:09 Its going to take 60 minutes of work, right. 1:12 Well, what if we have four people stuffing envelop simultaneously? 1:14 Each person only has to stuff 15 envelops, so it takes 15 minutes. 1:18 But the task hasn't gotten any smaller. 1:23 It's still 60 minutes of work even if it only took 15 minutes of time on the clock. 1:26 When we talk about time with computers, we're usually talking about the total work 1:31 time added up across all the computers that are working on the task together. 1:35 So how does all this relate to AWS? 1:40 Anything that you do on AWS will require some amount of space, 1:42 some amount of time, or both. 1:46 The price you pay is based on space multiplied by time. 1:49 In addition, you can usually trade space for time, at least to some degree. 1:52 Let's take a look at an example to understand what this means. 1:56 You and your friends are going on vacation and 2:00 you'll all be staying at the Amazon Hotel. 2:02 You need to decide how many rooms to book and 2:04 how many nights you'll be staying at the hotel. 2:06 At the Amazon hotel, you can book a regular room or a suite. 2:08 A suite has more space, but it costs more money than a regular room. 2:12 How do you make sure that you can stay at the hotel as long as possible 2:16 while not paying too much money? 2:19 You could all try to squeeze into one room. 2:21 This means that you'll be able to stay at the Amazon hotel for 2:23 a long time, because one room isn't very expensive. 2:25 However, you're sacrificing space to get that extra time, and 2:28 no one will sleep very well in that cramped space. 2:32 Alternatively, everyone could get their own room, or 2:34 even their own separate suite. 2:37 Now, everyone has a lot of space, but that gets expensive quickly and 2:39 you might only be able to afford one night at the hotel. 2:43 Effectively, you're sacrificing time to get that extra space. 2:46 The best approach is somewhere in the middle. 2:50 A small number of rooms and suites, shared so that everyone has just enough space 2:52 will make sure that you pay the minimum amount for the maximum benefit. 2:56