CS Fundamentals: MNC ka pehla filter

# 1. Operating Systems (OS)
✓ Computer kaise kaam karta hai internally
✓ Processes, Threads, Memory Management
✓ CPU Scheduling, Deadlocks, File Systems
✓ Real examples: Linux kernel, Windows scheduler

# Key Topics:
- Process vs Thread
- Context Switching
- Virtual Memory, Paging, Segmentation
- CPU Scheduling Algorithms
- Deadlock: Prevention, Avoidance, Detection
- Mutex, Semaphore, Monitors

# 2. Database Management Systems (DBMS)
✓ Data kaise store, retrieve, manage hota hai
✓ SQL, Transactions, Indexing, Normalization
✓ Concurrency Control, ACID properties
✓ Real examples: MySQL, PostgreSQL, MongoDB

# Key Topics:
- SQL queries (JOINs, GROUP BY, subqueries)
- B-Tree Indexing
- ACID Properties
- Normalization (1NF, 2NF, 3NF, BCNF)
- Locks, Deadlock in DBMS
- Transactions, Isolation Levels

# 3. Computer Networking (CN)
✓ Computers kaise communicate karte hain
✓ OSI Model, TCP/IP, HTTP, DNS
✓ Routing, Protocols, Security
✓ Real examples: Internet, WiFi, HTTPS

# Key Topics:
- OSI 7 Layers
- TCP vs UDP
- HTTP Methods (GET, POST, PUT, DELETE)
- DNS Resolution
- HTTPS, SSL/TLS
- IP Addressing, Subnetting

# Preparation Timeline:

Week 1: Operating Systems
✓ Day 1-2: Process, Thread, Context Switch
✓ Day 3-4: Memory Management (Virtual Memory, Paging)
✓ Day 5: CPU Scheduling
✓ Day 6: Deadlocks
✓ Day 7: Revision + Practice Questions

Week 2: DBMS
✓ Day 1-2: SQL (JOINs, Queries)
✓ Day 3: B-Tree Indexing
✓ Day 4: ACID, Transactions
✓ Day 5: Normalization
✓ Day 6: Concurrency (Locks, Deadlock)
✓ Day 7: Revision + Practice Questions

Week 3: Computer Networking
✓ Day 1-2: OSI Model, TCP/IP
✓ Day 3: HTTP, HTTPS
✓ Day 4: DNS, IP Addressing
✓ Day 5: Routing basics
✓ Day 6: Security (SSL, TLS)
✓ Day 7: Revision + Practice Questions

Week 4: Mixed Practice
✓ Top 50 CS questions practice
✓ Mock interviews
✓ Revision of weak areas

# Daily Strategy:
? 2 hours theory padho
? 1 hour questions solve karo
✓ Notes banao � key points
✓ Revision karo kal ke liye

# CS Interview Format:
? 30-45 minutes per subject
? 5-8 questions expected
✓ Mix of theory + practical

# Common Questions:
OS: "Process aur Thread mein kya difference hai?"
DBMS: "ACID properties explain karo"
CN: "TCP aur UDP mein kya difference hai?"

# How to Answer:
1. Definition do (1 line)
2. Example do (real-world)
3. Comparison (vs alternatives)
4. Use case (kab use karte hain)

# Example Answer:
"Process ek independent program hai jo apna
memory space rakhta hai. Jaise Chrome ka har
tab ek naya process hai. Thread process ke
andar ka lightweight unit hai � same memory
share karta hai. Browser mein har tab ek thread hai."

# Tips:
✓ Concepts clear karo, ratna mat
✓ Real-world examples do
✓ Diagrams banao (OSI model, memory layout)
? "Pata nahi" bolo agar nahi aata � but try karo
✓ Follow-up questions ke liye ready raho