Basic concepts of Amazon S3
Let's take a look at the basic S3 concepts:
Buckets
A bucket is a container in Amazon S3 where the files are uploaded. For using Amazon S3 to store a file, you need to create at least one bucket. Files (objects) are stored in buckets.
The following are a few features of buckets:
- The bucket name should be unique because it is shared by all users.
- Buckets can contain logical nested folders and subfolders. But it cannot contain nested buckets.
- You can create a maximum of 100 buckets in a single account.
- The bucket name can contain letters, numbers, periods, dash, and the underscore.
- The bucket name should start with a letter or number, and it should be between 3 to 25 characters long.
Buckets can be managed via the following:
- REST-style HTTP interface
- SOAP interface
The following bucket looks similar to the Amazon S3 bucket to which we will upload files (objects):
A bucket doesn't have any size restrictions for the user. It can store objects of any size.
Buckets can be accessed via HTTP URLs as follows:
http://< BUCKET_NAME>.s3.amazonaws.com/< OBJECT_NAME >http://s3.amazonaws.com/< BUCKET_NAME >/< OBJECT_NAME >
In the preceding URLs, BUCKET_NAME will be the name of the bucket that you provided while creating it. And OBJECT_NAME will be the name of the object that you provided while creating the object.
Objects
An object is a stored file in Amazon S3. Each object consists of a unique identifier, the user who uploaded the object, and permissions for other users to perform CRUD operations on it. Every object is stored in a bucket.
Objects can be managed via the following:
- REST-style HTTP interface
- SOAP interface
Objects can be downloaded via the following:
- HTTP GET interface
- BitTorrent protocol
The bucket can consist of any type of object, be it a PDF, text, video, audio, or any other kind of files.
Keys
While creating an object, a key will be assigned to the object. This key will be used for retrieving the object. The key should have the following features:
- Be unique in the bucket
- Contain alphabets, numbers, and special characters such as
-,!,_,.,*,',(, and)
