The Cloud is a technical platform that provisions hardware and software over the wire.
So let us explain that idea by a well-known concept from daily life: Power over the electrical grid.
You have several suppliers that are delivering all pretty much the same product (electrical power). They deliver as much power as you need, and you pay only for the units consumed.
That same principle is underlying the cloud idea, consume Hardware and Software as you need it. So you don't have to buy servers or licenses upfront, you simply consume those items in the quantities you need.
If you buy hardware, you have to evaluate at a certain point in time what is the maximum capacity needed in the future. Well you can't predict that with high accuracy, so you probably stick to buy more than you need. Most of the time the hardware isn't used in full, so you pay for capacity that you don't use.
If you buy software, you have to pay license fees upfront and have recurring update costs.
Microsoft Azure has several security layers that protect your data, apps and infrastructure. We do not want to explain them in detail here, but we want to give you an idea of the different layers implemented.
When designing data centers security best-practices and the knowledge of Microsoft's experts were taken into account to minimize the risk of attacks and malicious actions.
Microsoft Azure provides various functions to protect applications, data and infrastructure. These include a physical monitoring and management of data centers around the clock, as well as automatic updates and the automated use of current antivirus software. Additional protection is provided by encrypted communication and reliable access control.
To test infrastructure and applications for security vulnerabilities, penetration tests are conducted on a regular basis as well as on-demand. In these tests the behavior of an attacker is simulated, so that the insights can be used to further improve security.
If you want to know more, we recommend to visit the Microsoft Azure Trust Center.