Difference between Routing and Forwarding
Routing: Routing is the process of selecting the best path for data packets to travel from source to destination across a network. It is a control-plane function and is performed using routing algorithms and routing tables (e.g., OSPF, RIP, BGP).
Forwarding: Forwarding is the process of moving a packet from an incoming interface to the correct outgoing interface based on the forwarding table. It is a data-plane operation and happens very fast inside the router.

Key Distinction
Routing decides which path to take, while forwarding decides how to send the packet on that path.

Advantages of Network-Specific Routing over Host-Specific Routing
1) Smaller Routing Table: Network-specific routing stores routes for entire networks instead of individual hosts, reducing routing table size.
2) Faster Lookup: Fewer entries in the routing table make route lookup faster and more efficient.
3) Better Scalability: It scales well for large networks like the Internet where millions of hosts exist.
4) Lower Overhead: Less memory and processing power are required compared to host-specific routing.
5) Easier Management: Network administrators can manage routes more easily by handling networks instead of individual hosts.

Paging
Paging is a memory management technique used by the operating system where a process’s logical memory is divided into fixed-size blocks called pages, and physical memory is divided into frames. Pages are loaded into frames as needed, allowing non-contiguous memory allocation and efficient use of RAM.

Thrashing
Thrashing is a condition in a demand-paged system where the operating system spends most of its time handling page faults (swapping pages in and out of memory) instead of executing processes. This happens when there are not enough frames to hold the working sets of active processes, leading to very low CPU utilization and poor performance.

Role of Address Resolution Protocol (ARP) in TCP/IP
Address Resolution Protocol (ARP) is used to map a logical IP address to a physical MAC address within a local network. Although ARP works closely with the network layer, it operates between the Network Layer and the Data Link Layer of the TCP/IP protocol suite.

Main Functions of ARP
1) IP to MAC Mapping: ARP finds the MAC address corresponding to a given IP address so that data can be delivered on the local network.
2) ARP Request: When a device wants to send data, it broadcasts an ARP request asking, “Who has this IP address?”
3) ARP Reply: The device with the matching IP address responds with its MAC address.
4) ARP Cache: The resolved IP–MAC pairs are stored temporarily to reduce future ARP requests and improve efficiency.

Importance of ARP
Without ARP, devices would not be able to communicate over a local network because physical delivery of packets requires MAC addresses.

(i) Bandwidth
Bandwidth refers to the maximum amount of data that can be transmitted over a network channel in a given amount of time. It is usually measured in bits per second (bps).

(ii) Latency
Latency is the time delay between sending data from the source and receiving it at the destination. It is commonly measured in milliseconds (ms).

(iii) MAC Address
A MAC (Media Access Control) address is a unique physical identifier assigned to a network interface card (NIC) by the manufacturer. It is used for communication within a local network.

(iv) IP Address
An IP (Internet Protocol) address is a logical address assigned to a device on a network that identifies it uniquely and enables communication across networks.

ACID in Database System
ACID represents a set of properties that ensure reliable processing of database transactions. It helps maintain data consistency and integrity in a database system.

A – Atomicity
Atomicity ensures that a transaction is treated as a single unit. Either all operations of the transaction are completed successfully, or none of them are applied to the database.

C – Consistency
Consistency ensures that a transaction brings the database from one valid state to another valid state, following all defined rules and constraints.

I – Isolation
Isolation ensures that multiple transactions executed concurrently do not interfere with each other. Each transaction appears to be executed independently.

D – Durability
Durability guarantees that once a transaction is committed, its changes are permanently saved in the database, even in case of system failure.

Condition for a Deadlock-Free System
To ensure that a system is free from deadlock, the following condition must be satisfied:

r ≥ P × (m − 1) + 1

Where:
• P = Number of processes
• m = Maximum number of resources each process may request
• r = Total number of available resources

Function Overloading
Function overloading is a concept where multiple functions have the same name but different parameters (either in number or type). It is resolved at compile-time, so it is also called compile-time polymorphism.

Example

class Math {
public:
    int add(int a, int b) { return a + b; }
    float add(float a, float b) { return a + b; }
};

In this example, the add() function is overloaded to work with both integer and float values.

Function Overriding
Function overriding allows a derived class to provide its own implementation of a function that is already defined in its base class. It is resolved at runtime and requires inheritance and virtual functions.

Example

class Base {
public:
    virtual void display() { cout << "Base class display"; }
};

class Derived : public Base {
public:
    void display() override { cout << "Derived class display"; }
};

Here, the display() function in the derived class overrides the base class version.