01
Programming fundamentals
Programs combine data, control flow, reusable functions, and input/output.
- Variables name values.
- Conditionals choose between paths.
- Loops repeat work; functions package reusable behavior.
Edvora/Computer Science
SUBJECT HUB
Computer Science
Programming, algorithms, web fundamentals, data, networking, and responsible security concepts.
CORE TOPICS
Build the foundation.
These are concise review notes—not a replacement for your course textbook or teacher’s instructions.
02
Python basics
Python uses indentation to define blocks and supports common data types such as numbers, strings, lists, dictionaries, and booleans.
- Use == for comparison and = for assignment.
- Functions are declared with def.
- Exceptions represent runtime error conditions that code can handle.
03
Data structures
Choose a structure based on how the program needs to store, access, and update data.
- Lists preserve sequence and allow indexed access.
- Dictionaries map keys to values.
- Sets model unique items and efficient membership checks.
04
Algorithms
An algorithm is a repeatable procedure for solving a class of problems.
- Correctness comes before optimization.
- Measure time and space growth as inputs scale.
- Break large problems into smaller steps.
05
How the web works
Browsers request resources from servers using HTTP or HTTPS after resolving hostnames through DNS.
- HTML describes document structure.
- CSS controls presentation.
- JavaScript adds client-side behavior.
06
Networking
Networks move data between endpoints using layered protocols and addressing.
- IP identifies network interfaces for routing.
- TCP provides reliable ordered delivery for many applications.
- DNS maps names to records used to reach services.
07
Databases
Databases organize persistent data so applications can query and update it consistently.
- Relational databases organize data into tables.
- Keys help identify rows and relate tables.
- Queries should request only the data an application needs.
08
Security foundations
Security starts with clear boundaries, least privilege, updates, authentication, and careful handling of untrusted input.
- Keep secrets out of client-side code.
- Validate input and encode output for the correct context.
- Test only systems you own or are explicitly authorized to assess.
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