2.8 Explain licensing concepts.
📘CompTIA Server+ (SK0-005)
In IT, licensing determines how software can be used legally. Organizations must follow the rules set by software vendors to avoid fines or losing support. Licenses often depend on how software is installed, how many users access it, or the hardware it runs on.
Below are the main licensing models:
1. Per-instance
- What it is: A license is required for each separate installation (instance) of the software.
- How it’s used:
- Example: A company wants to install a database server. Each installation on a server requires a separate license.
- If you install the database on three servers, you need three licenses.
- Key point: Count installations, not users or machines accessing it.
2. Per-concurrent user
- What it is: A license allows a certain number of users to access the software at the same time.
- How it’s used:
- Example: A remote desktop application allows 10 concurrent users. If 20 employees have accounts but only 10 log in at the same time, only 10 licenses are needed.
- Key point: This is ideal for applications where not everyone uses the software simultaneously.
3. Per-server
- What it is: The license is tied to a specific server. All users accessing the software through that server are covered.
- How it’s used:
- Example: A file-sharing application installed on Server A requires one license for Server A, regardless of the number of users accessing it.
- Key point: Focuses on the server itself, not individual users or devices.
4. Per-socket
- What it is: A license is based on the CPU socket on a server. Each physical processor socket requires a license.
- How it’s used:
- Example: A server has 2 CPU sockets. If software is licensed per-socket, you need 2 licenses.
- Key point: Used by enterprise software, often for high-performance servers.
5. Per-core
- What it is: A license depends on the number of CPU cores rather than sockets.
- How it’s used:
- Example: A server has 2 sockets, each with 8 cores. Per-core licensing may require 16 licenses (or a multiple, depending on vendor rules).
- Key point: Provides more precise scaling for modern multi-core processors.
6. Site-based
- What it is: A license covers all users or devices at a specific physical location.
- How it’s used:
- Example: A company office in New York can have unlimited use of a software package under a site license.
- Key point: Simplifies management for large offices; only works for users at that site.
7. Physical vs. virtual
- Physical license: Tied to a physical server or machine.
- Virtual license: Tied to a virtual machine (VM) in a virtualized environment like VMware or Hyper-V.
- How it’s used:
- A physical license might not cover VMs unless the vendor allows it.
- Some vendors provide separate virtual licenses or allow a license to move between VMs.
- Key point: Important in data centers using virtualization—license rules can differ for physical vs. virtual deployment.
8. Node-locked
- What it is: The license is locked to a specific device or computer.
- How it’s used:
- Example: A software installed on one workstation can only run on that workstation.
- Key point: Often enforced via hardware ID or MAC address. Limits flexibility but prevents unauthorized copying.
9. Signatures
- What it is: A licensing method based on digital signatures or activation keys to validate software.
- How it’s used:
- Example: Office applications, security software, or cloud apps often require a key or digital certificate to activate.
- The software checks the signature to ensure it’s genuine.
- Key point: Protects against piracy and ensures only licensed users can run the software.
Summary Table for Quick Exam Recall
| Licensing Model | What It Counts / Controls | Example Use Case |
|---|---|---|
| Per-instance | Each installation | Database on multiple servers |
| Per-concurrent user | Users logged in simultaneously | Remote desktop software |
| Per-server | Each server | File server application |
| Per-socket | CPU sockets | High-performance enterprise apps |
| Per-core | CPU cores | Modern multi-core servers |
| Site-based | All users at a site | Office software for a corporate branch |
| Physical vs. virtual | Server type (physical or VM) | Virtualized data center software |
| Node-locked | Specific device | Workstation software locked to a PC |
| Signatures | Digital key / activation | Microsoft Office, antivirus, cloud apps |
✅ Exam Tips:
- Always read whether the software counts users, servers, cores, or locations.
- Virtual vs. physical licenses are often tested—know the difference.
- “Per-concurrent user” is about simultaneous usage, not total users.
- Node-locked licenses are the most restrictive; site-based licenses are the most flexible.
