Information Systems Fundamentals

Systems

Enterprise resource planning (ERP): integrated, single database. Batch = efficient, not current; real-time = current, needs strong input controls.

Cloud

• Infrastructure as a service (IaaS) → customer manages operating system and up.
• Platform as a service (PaaS) → customer manages apps and data.
• Software as a service (SaaS) → customer manages data, access, configuration.
• Customer is always responsible for its data and access.
• Public · private · community · hybrid.

Continuity

• Business continuity plan (BCP) = business functions; disaster recovery plan (DRP) = systems and data.
• Recovery time objective (RTO) = max downtime. Recovery point objective (RPO) = max data loss.
• Hot (hours) · warm (days) · cold (weeks).
• Backups: full, incremental, differential; 3-2-1 rule; test restores.

Networks

Local area network (LAN) · wide area network (WAN) · virtual private network (VPN, encrypted remote access) · application programming interfaces (APIs) need authentication.

Exam traps

• RTO is about time to restore; RPO is about how much data you can afford to lose, which drives how often you back up.
• Incremental backups are quickest to run but slowest to restore (the full backup plus every incremental); a differential restore needs only the full backup plus the latest differential.
• A VPN encrypts data in transit; it doesn't protect data stored on the device.