Software as a Service (SaaS) is software you use through a browser or app and pay for as a subscription, while the provider runs the servers, updates and backups. Webmail, accounting software, CRMs and website builders are everyday examples. This guide explains how SaaS works, what it genuinely saves you, the risks to plan for, how to choose and roll out a SaaS product, and what to think about if you are building one.
SaaS means you rent finished software instead of installing it: no servers to run and updates arrive automatically, but you depend on the provider for uptime, pricing and your data. Before you sign up, check that you can export your data, that the provider protects personal data as India's DPDP Act 2023 expects, and that it supports two-factor login and GST invoices. If you are building a SaaS product, start on a managed platform and move to your own server only when you need the control.
1. What SaaS is, and what it is not
With traditional software you buy a licence, install it on your own computers or server, and look after updates and backups yourself. With SaaS the provider runs one copy of the application in the cloud, and you log in to use it. You pay monthly or yearly, per user or per plan.
SaaS is one of three cloud service models:
| Model | You get | You manage | Example |
|---|---|---|---|
| IaaS (Infrastructure) | Virtual servers and storage | The operating system, software, security and data | A VPS |
| PaaS (Platform) | A place to run your own code | Your code and data | An app hosting platform |
| SaaS (Software) | A finished application | Your account, users and data | Webmail, accounting software, a website builder |
For more on the three models, see Cloud computing explained.
2. What SaaS genuinely saves you
- No upfront hardware or installation. You start in minutes and pay as you go.
- Updates arrive automatically. Security fixes and new features appear without you doing anything.
- Access from anywhere. A browser and an internet connection are enough, and teams can work on the same data.
- Scaling is a plan change. Adding users or capacity means changing your subscription, not buying a server.
These are real, but they are not free. You pay every month for as long as you use the software, and over several years a subscription can cost more than a one-time licence.
3. The risks to plan for
- Small teams without IT staff
- Standard tasks: email, accounts, CRM, websites
- Starting quickly and paying monthly
- Your data lives on someone else's servers
- Outages and changes are outside your control
- Price rises and per-user costs that grow with your team
- Lock-in if you can't export your data in a usable format
"Top-tier security" is not automatic either. The provider secures its platform; you are still responsible for strong passwords, two-factor login, who has access, and removing people who leave.
4. How SaaS works behind the scenes
Most SaaS products are multi-tenant: one application serves many customers, and each customer's data is kept separate by the software. Providers do this in different ways.
| Design | How data is separated | Trade-off |
|---|---|---|
| Shared database, tenant ID on every row | The application filters every query by customer | Cheapest to run; a coding mistake can expose another customer's data |
| Schema or database per customer | Each customer has its own schema or database | Stronger separation; more to manage and migrate |
| Single-tenant (one copy per customer) | Each customer gets its own installation | Strongest separation; most expensive |
As a buyer, you rarely see this, but it explains why security testing and access control matter so much to a SaaS provider. See Security auditing for SaaS applications.
Good SaaS products also connect to others through APIs and webhooks, so your invoicing tool can talk to your payment gateway and your CRM. Check what integrations a product offers before you commit.
5. How to choose a SaaS product
Ask these questions before you sign up:
- Can I export all my data in a standard format (CSV, JSON, MBOX) at any time, including after I cancel?
- How is personal data handled? If you store customers' personal data, India's Digital Personal Data Protection Act 2023 applies to you. Ask the provider where data is stored, who can access it and how breaches are reported. This is general information, not legal advice.
- Does it support two-factor login and roles, so each person gets only the access they need?
- What does it really cost? Per-user prices, annual discounts, add-ons, and whether GST invoices are issued with your GSTIN.
- What happens when it is down? Look at the provider's status page history, not only its promises.
- Is there a free trial, so you can test with real work before paying?
6. Rolling it out well
- Start with one team and a real task, not a demo.
- Set up roles and two-factor login before you invite everyone.
- Train people on the few features they will use daily.
- Keep your own backup: export important data on a schedule.
- Review every few months: remove unused accounts, check who is an admin, and cancel tools nobody uses.
7. If you are building a SaaS product
A SaaS product is a web application with accounts, billing and multi-tenant data. A practical path for a small team:
- Start on a managed platform so you spend your time on the product, not on servers. On the Domain India App Platform, Node.js apps are detected automatically, and Python, PHP and other languages run from a Dockerfile; plans include a PostgreSQL database. It does not support WebSockets, so real-time features need another approach or a VPS. See Getting started with the App Platform.
- Move to a VPS when you need full control: background workers, Redis, WebSockets or your own database tuning. A VPS is self-managed.
- Build security in from the start: tenant isolation in every query, two-factor login, audit logs and regular testing.
- Plan for data protection under the DPDP Act 2023 if you handle Indian users' personal data.
For the difference between platforms, see Platform as a Service explained.
8. Where Domain India fits
Domain India offers SaaS you can use today and platforms to build your own. The AI Website Builder builds and hosts a business website for you, and Business Email gives you mail at your own domain with webmail, calendar and contacts. To run your own SaaS product, the App Platform and VPS plans are the starting points. Cards show live prices, excluding 18% GST.
- 512 MB RAM per app
- 1 vCPU
- 5 GB NVMe SSD
- PostgreSQL Database
- Priced per mailbox - start with one
- Email at your own domain ([email protected])
- Add and remove mailboxes yourself
- Webmail with calendar, contacts and tasks
Frequently asked questions
What is SaaS in simple words?
SaaS, or Software as a Service, is software you use over the internet and pay for as a subscription. The provider runs the servers, installs updates and keeps backups; you just log in through a browser or app.
What is the difference between SaaS, PaaS and IaaS?
IaaS rents you servers that you manage completely. PaaS runs your own code without you managing servers. SaaS gives you finished software that you simply use.
Is SaaS secure?
It can be, but security is shared. The provider protects its platform, and you protect your accounts with strong passwords, two-factor login and careful access control.
What should I check before choosing a SaaS product?
Check that you can export all your data, how personal data is stored and protected, whether two-factor login and roles are supported, the full cost including GST and add-ons, and the provider's outage history.
Does India's DPDP Act apply to SaaS tools I use?
If you collect personal data of people in India and store it in a SaaS tool, the Digital Personal Data Protection Act 2023 applies to you as the business responsible for that data. Choose providers that can support your obligations, and take legal advice for your situation.
Where can I host my own SaaS application?
A managed app platform lets you deploy code without running servers, and a VPS gives you full control. Domain India offers both: the App Platform for Node.js and Dockerfile-based apps, and self-managed VPS plans.
Ready to build or buy? See the App Platform, VPS plans, the AI Website Builder and Business Email.
Deploy your Node.js or Dockerfile-based app with a PostgreSQL database and free SSL, and focus on your product instead of servers.
See App Platform plans