There are four basic ways a business can make apps for a company: 1) on-premises solutions, 2) infrastructure-as-a-service solutions, 3) platform-as-a-service solutions, and 4) software-as-a-service solutions.
On-premises solutions require the IT department to build the entire solution on its own, from the servers to the code database. While that means granular control of hardware, software, infrastructure, and networking, it’s expensive, time consuming, and resource-intensive. Upgrades are hard to manage and it’s not always easy to move the technology forward in pace with changing business needs.
Infrastructure as a service (IaaS) provides raw data center capacity so that IT can take advantage of virtual machines, managed storage and networks, shared physical and network security. IaaS also means IT benefits from utility pricing that changes proportionally as you scale. However, IaaS still requires heavy IT involvement for integrating data, as well as building and maintaining apps and users.
Platform as a service (PaaS) offers everything IaaS delivers, as well the operating systems, middleware, runtime, and most importantly, highly configurable prebuilt visual development tools that allow IT and others in the business to build and deploy apps quickly, and integrate data from other sources like SAP and Oracle, and the tools and services to manage it all.
Software as a service (SaaS) delivers packaged apps that are ready to go for users with a web browser and internet access. The apps, built on a cloud database from an underlying platform, typically deliver software on a monthly subscription. Salesforce has been a leader in SaaS since 1999.
Salesforce was the first company to deliver PaaS to companies around the world, and it delivers it as few others do or can.