Multi-tenancy in cloud computing is exemplified by services like Gmail, Netflix, and Salesforce, where a single instance of software serves multiple customers (tenants) who share the same underlying infrastructure but have their own isolated data. Public cloud providers such as AWS and Microsoft Azure also use multi-tenancy, allowing many different users to run their virtual machines and applications on the same physical hardware, with strict security and isolation between them.

Software as a Service (SaaS)

**Email and Productivity:**

Services like Gmail and Microsoft 365 host millions of users on shared infrastructure, ensuring each person's inbox, documents, and settings are separate and secure.

**Streaming Services:**

Netflix and YouTube use a multi-tenant architecture to serve countless users simultaneously. Each user has their own profile and viewing history, but they all access the content from a shared platform and data center.

**CRM and Business Software:**

Salesforce and Workday are examples of multi-tenant SaaS applications. Multiple companies use the same platform, but the software ensures that each company's customer data and business processes remain isolated.

**Online Storage:**

Services like Dropbox and Google Drive allow many users to store files in the cloud, sharing the backend storage infrastructure while keeping each user's files private.

Infrastructure as a Service (IaaS)

**Public Cloud Providers:** Amazon Web Services (AWS), Microsoft Azure, and Google Cloud use multi-tenancy to allow different customers to run their own virtual machines, storage, and databases on the same physical servers. Customers' data and workloads are kept completely separate even though they are running on shared hardware