IT Infrastructure & Cloud Fundamentals Notes

IT infrastructure = Applications, Hardware, Networks, and Physical Plant that delivers services to an organization (the Technology Stack).

Main components: CRAC (Computer Room Air Conditioning), LAN (Local Area Network), UPS (Uninterruptible Power Supply), Electrical Generators, Server, Storage, SAN (Storage Area Network).
Data center concepts: physical plant and supporting IT infrastructure.

3 delivery methods: On-Premise/Company specific, Cloud, Hybrid (mix of Cloud and On-Premise).

Electricity and IT services are critical for business operations.
Cloud asks: Which is more cost-effective, scalable, and reliable? DIY (on-prem) vs rely on a utility (cloud model).

Definition: On-demand delivery of compute power, database, storage, applications, and other IT resources via the internet with pay-as-you-go pricing.
IT services become a utility: you get as much as you want when you need it.
Value comes from economies of scale in the cloud.

Public cloud IaaS and software spending trends show growing adoption from 2015 to 2026 (illustrative).
Cloud savings can be immense, though specific savings vary; real-world experience often cites large but context-dependent gains.
A common example shows substantial cost comparisons between On-Premises and cloud over multi-year horizons.

Public cloud infrastructure spending includes IaaS hardware and infrastructure software and SaaS/PaaS components.
Major cloud market players and growth dynamics influence pricing, services, and choices.

AWS, Microsoft Azure, and Google Cloud lead the market, with shifting shares over time.
Understanding market share helps contextualize features, pricing, and support ecosystems.

On-Prem CRM: highly customizable, but expensive.
Cloud CRM: quickly deployed, lower customization cost, and lower ongoing expense.
Relative comparison: Cloud often cheaper by a factor (illustrative).

Salesforce: ~23.9\% market share (example data).
Oracle, Microsoft, SAP, Adobe: remaining shares in the single to low double digits.
The exact shares evolve; cloud CRM dominance has grown.

Security concerns (≈ 81\% respondents).
Data loss and leakage risks; Regulatory compliance; Integration with IT environment.
Legal concerns; Perceived cost; Visibility into cloud resources; Migration challenges; Lack of cloud expertise; Lack of staff; Vendor lock-in.
These concerns explain partial adoption and ongoing risk management.

Company: Capital One, a bank holding company.
Breach: a mis-configured firewall allowed access to data hosted on AWS; 106 million credit card applications affected.
Data lost: names, addresses, emails, self-reported income.
Hacker: arrested; stock impact and market cap loss occurred after disclosure.

CUSTOMER RESPONSIBILITY for security in the cloud:
- Customer data, platform, applications, IAM (Identity & Access Management)
- OS, network & firewall configuration, client-side data encryption & integrity
- Authentication, compute, server-side encryption (filesystem/data), network protection (encryption, integrity, identity)
AWS RESPONSIBILITY for security of the cloud:
- Physical security of data centers, hardware/software infrastructure, virtualization, and underlying services
- Regions, availability zones, edge locations, global infrastructure
Summary: Security in the cloud is a shared responsibility; both customer and provider have duties.

AWS Region: geographic area; data replication across Regions is customer-driven; Regions have multiple Availability Zones; Regions provide redundancy.
Availability Zone (AZ): fully isolated partition of AWS infrastructure; discrete data centers; designed for fault isolation; interconnected via high-speed private networks; you select AZs for deployment.
Data centers: designed for security, redundancy, and reliability; typical data center size includes tens of thousands of servers.

Factors: data governance/legal requirements, proximity to customers (latency), available services, and cost/price differences by region.

Data centers are secured facilities with redundant power, networking, and connectivity.
Each data center houses thousands of servers and is part of a larger region/ AZ structure for resilience.

What is a server? A specialized computer connected to a network that provides resources or services to clients.
Server types example: Tower, Rack-mounted, Blade compute systems.

Serve resources to clients over a network (e.g., the Internet or internal networks).

An EC2 instance is an AWS virtual server; you can create one quickly to run applications.