BLOB storage is short for

S3 buckets have a maximum total size of all objects combined that they can hold

The Microsoft Azure offering for BLOB storage is called

S3 needs to recognize the file type of the data you upload (either via the file suffix or using the magic bytes at the file start), otherwise it cannot correctly store the data.

S3 storage is mounted like file systems, so only one client can use an S3 bucket at the same time.

You want to update small parts of an already existing object on S3. You do so by

There is a minimum storage duration of uploaded S3 objects. They can only be deleted again after 7 days earliest.

You want to run analytics on EMR that take roughly 30 minutes per day. Ideally, you will

A SerDe implements how to read and interpret the data format you have stored on S3 and  want to analyze. If you have a seldomly used and/or proprietary data format, you can implement and use your own SerDe.

Schema-on-read means

"Everything is an API call" means that

You launch an EC2 instance in the AWS region us-east-1 (North Virginia). You then send an API call towards the AWS region eu-north-1 (Stockholm) and ask to list all running EC2 instances. The API response will show your instance. 

The term "column4" in the following SQL query is a ...?

SELECT column1, column2, column4

FROM mytable

WHERE

  column1 = ‘value1’

  AND column2 > 20

LIMIT 100;