- LPU MCA Semester 1
- CAP470
- Unit 1
CAP470 · Unit 1: Introduction to cloud computing
Cloud overview, definition and evolution of cloud computing
10 practice questions · in the MTE and ETE syllabus
Key points
- NIST defines cloud as on-demand access to a shared resource pool
- Mainframe, client-server, grid and utility computing led to cloud
- Virtualization and broadband made cloud practical
- Cloud adds self-service and elasticity to utility ideas
Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (servers, storage, networks, applications and services) that can be provisioned and released quickly with minimal management effort. This is the NIST definition (SP 800-145).
Evolution: mainframes with time-sharing, then client-server computing, then grid computing (many machines cooperating on large jobs) and utility computing (metered, pay-for-use resources like electricity), made practical by virtualization and fast broadband. Cloud combines these ideas with self-service and elastic scaling. Early commercial milestones include Amazon's S3 and EC2 in 2006.
| Era | Idea |
|---|---|
| Mainframe | central machine, shared terminals |
| Client-server | work split between clients and servers |
| Grid | distributed machines on a common task |
| Utility | pay for what you use |
| Cloud | self-service, elastic, metered, virtualized |
Exam trap: cloud is not just hosting; elasticity, self-service and metering are what make it cloud.
Try two questions
Which sequence best describes the historical path that led to cloud computing?
- Cloud, then mainframes, then client-server, then grid computing
- Grid computing, then cloud, then mainframes, then client-server
- Mainframes, client-server, grid and utility computing, then cloud
- Client-server, then mainframes, then cloud, then utility computing
Show the answer
C. Computing moved from centralised mainframes to client-server, then to grid and utility ideas, which cloud builds on.
Why not A: Cloud is the most recent stage, not the first.
Why not B: Mainframes came first, and cloud came after grid computing.
Why not D: Mainframes preceded client-server, and utility computing preceded cloud.
Which idea from earlier computing eras treats computing like electricity, billed by how much is used?
- Distributed denial-of-service computing
- Batch-only mainframe computing with fixed charges
- Peer-to-peer file sharing with no billing at all
- Utility computing
Show the answer
D. Utility computing offers metered, pay-for-use resources, an idea that cloud adopted.
Why not A: That is a type of attack, not a billing model.
Why not B: Mainframes were typically billed on fixed or scheduled terms.
Why not C: Peer-to-peer sharing is not a metered utility model.