Global service, accessible from anywhere.
Public service, unlimited data, multi-user.

S3 objects

Like file.
Key: koala.jpg (like file name)
value: content being stored (0-5TB)

S3 buckets

Created in separate region. Needs to be globally unique. 3-63 chars, all lower case, no underscore. starts with number or lower case. can’t be like ip address (1.1.1.1)
Buckets (100 per account/1000 hard limit)
Unlimited objects in bucket.
Bucket created in region never leaves that region. Data sovereignty. Rules/Laws of that particular region apply.
Flat structure (Everything stored at root level)
Folder structure can be named like and S3 shows it like so:
/old/koala.jpg
koala1.jpg

references: