 So students, in this module, we will start with an introduction to the storage services on the Amazon Web Services. And let's look at the module coverage. So introduction to the Amazon Web Services Storage and differentiating between different options. And object storage and key value storage, they are different. Key value storage is in a certain way similar to the databases. And I will do a comparison of this service key based with the databases. Of course, it is very different also. Biggest difference is that this does not support join. This does not support join because it is not a relational database, so to say. So let's go ahead. So when you store a data on the Amazon cloud, okay, on S3, which is the simple storage service, the data is stored as bytes, okay, bytes means that it is it for the Amazon Web Services, it is just bytes, it could be image, it could be audio, it could be MRI scans, which require a certain software to read them, okay. And this was the first service which was offered by Amazon Web Services. And remember that it has many, many storage services. So if you look at the module number 164, slide number 11, you will see number of such services which are related to the storage. And the one of them is the Glacier, which is for the archival services, right? So why it is so popular? Why Amazon Web Services with a storage is popular, I'll tell you why. There are many limitations of the traditional storage services. What are those limitations? Over here, I look at three limitations, scaling, speed and cost, scaling, speed and cost. The traditional data storage cannot scale so so well with reference to what is produced today and what people and the companies like to store, okay. The scaling is not there, the scale is not there, the growth level is not there. Then is the speed, because if all that data in terabytes, if that is stored on the web services, servers of the company, okay, or somewhere else using the traditional approach, okay, that congest the network, that congest the network, all right. And then the cost is there, the traditional systems are nowhere cost effective as compared to the Amazon Web Services that we have discussed and will also discuss in subsequent modules also, because of the sharing, because of the network effect, because of so many people coming over the Amazon Web Services, this cost of storage is advertised, and it is very low, okay. There has been change, okay, network associated service storage or storage area networks, they have been around for a while, but they cannot keep up the pace with what is being generated and what the companies want to store, what the individuals want to store. That is why we look at the Amazon Web Service Storage Services. So as I said before, it's a collection of photos, videos, it imposes no structure. You just store the bytes, okay, and user to know the object format and the manipulation methods, how, what tool is going to be associated with what has been stored, what application will run it, that is the responsibility of the user. For the Amazon storage, these are just bytes, remember, these are just bytes. It could be an image, it could be audio, it could be animation, as I said, it could be MRA scans also. And it is continuous data appending, this is not like the conventional storage where I can make changes, okay, and those changes are stored. Remember the big difference, the data is appended. And as I will discuss in the subsequent modules, we use the versioning approach to keep track of the changes and to get those changes. And there is no update functionality, there is no update. Insert retrieve, insert retrieve, insert and retrieve, update is not there, remember this. So this key value storage is somewhat similar to the databases, why? Because there is a key which is associated with all the records, which are similar. But if you are looking at the records which don't have a key, then you have to scan through all the records. For example, if I'm looking at the addresses and the key is not associated with the addresses, then I will have to scan all those records because the key is not there. So the retrieval is restricted to the key value. And finally, if I need to combine the tables, if I have table one, table one, table two, table three, I want to combine them like this, combine them like this, to perform a join that is not there in Amazon Web Services, storage services. You have to do some working over there to combine the data from these tables to generate a collective or a comprehensive or a joined view or a joined result that is not there.