Let's go straight to the point
First, the concept goes.
IaaS : Infrastructure as a service,
Infrastructure-as-a-service
PaaS : platform service, Platform-as-a-service
SaaS : software service, Software-as-a-service
IaaS
Infrastructure as a service. With IaaS, when an enterprise develops an app, it only needs to register an account on the public cloud platform, spend some money, and configure various cloud servers, storage of various sizes, and networks of various bandwidths. Computer room site selection, equipment procurement, physical servers, storage, network and other issues can be solved with only one account.
As a programmer, you only need to install various runtimes, middleware, databases, etc. on the server and develop the front-end and back-end of this APP, test, go online, iterate, and update. If there is no IaaS, our early stage There is still a lot to do.
PaaS
Platform as a Service. PaaS is based on IaaS, which solves the construction and operation problems of operating system, database, runtime environment, middleware, and various frameworks. With PaaS, programmers only need to concentrate on developing their own APP.
SaaS
Software as a service. SaaS is ready-made, and there is no need for development at all. Merchants only need to focus on their own business, and other things such as writing codes and maintenance are left to SaaS manufacturers. Users only need a renewal account, and all problems are solved.
All three have very large product groups and user service groups, and have also formed the cornerstone of major manufacturers. The characteristics among the three are also very obvious.
service level difference
IaaS, providing the lowest-level service . Closest to server hardware resources, so that users can access the network itself with the greatest degree of freedom;
PaaS, providing a higher level of service . The overall service hides the underlying network, storage, operating system and other technical issues from the user, that is to say, the underlying service is transparent to the user, and what is open to the user is the development and operating environment of the software itself;
SaaS, providing the top-level service . Most users will use simple clients to invoke services at this level. Users can customize business models from suppliers through the Internet according to their own needs. Some simple examples are Google documents, forms, and so on.
Is it that you haven't fully understood yet?
But wait, there is more.
The 9 big pieces needed to develop software:
For people who use software, the first column, [Application] and [Data], is the closest part to us.
For example: we submit an reimbursement application in a certain nail, in fact, we upload our own reimbursement data to the application.
In the third column, [Virtualization], [Server], [Storage], and [Network] are the basic conditions for making software. Except for virtualization technology, everything else is hardware, so in the field of cloud computing, this piece is called infrastructure. .
These can be seen in the engine room.
The ones in the middle are platforms built using the rightmost infrastructure to carry the leftmost [application] and [data].
Therefore, from right to left is a process of gradually softening hardware (software development), and IT technology plays a necessary role in this process:
but!
Not all companies have the capital to develop a software independently (no one will work if money, people, or strength are lacking).
Therefore, cloud services were born.
Must Read: Three Cloud Services
Large and small enterprises have different financial resources and different problems, so there are always various needs for software development.
After evolution, cloud services are gradually divided into three categories:
IaaS : Infrastructure as a service,
Infrastructure-as-a-service
PaaS : platform service, Platform-as-a-service
SaaS : software service, Software-as-a-service
As shown in the picture:
In the process from IaaS to SaaS, the cost that enterprises need to pay is getting smaller and smaller, and the degree of cloudification is getting higher and higher.
Finally, I borrowed a very good answer from Zhihu and used it as an example to illustrate the difference between the three.
Those who choose to make their own pizza at home, what he does is the first column above, local deployment, also called privatization deployment.
If he chooses to buy finished products to make pizza at home, the service he chooses is the second column above, infrastructure services, that is, IaaS.
If you choose to order takeaway pizza, that is the third column, the buyer of the platform as a service, that is, PaaS.
If you choose to go directly to the pizza shop to eat, it is software as a service, and the buyer in the last column is SaaS.
This time, I understand~