The OSI (Open Systems Interconnection) Model is a conceptual framework that standardizes the functions of a network communication system by dividing it into seven distinct layers. These layers ensure seamless communication between different systems and networks by defining protocols and packet transfer processes.

Difference Between OSI and TCP/IP Model:

Subnet Mask

A subnet mask is a 32-bit number used to divide an IP address into network and host portions. It helps determine which part of the IP address identifies the network and which part identifies the device within that network.

Example: 255.255.255.0

Localhost IP Address

The localhost IP address refers to the local machine itself. It is used to test network applications on the same device.

Localhost IPv4: 127.0.0.1

• Meaning: HTTP = HyperText Transfer Protocol, HTTPS = HyperText Transfer Protocol Secure.
• Security: HTTP is not encrypted, HTTPS is encrypted using SSL/TLS.
• Data Protection: HTTP data can be intercepted, HTTPS protects against eavesdropping and tampering.
• Port: HTTP uses port 80, HTTPS uses port 443.
• Certificate: HTTP does not require a certificate, HTTPS requires a digital certificate.

NAT (Network Address Translation)

NAT is a networking technique that allows multiple private IP addresses within a local network to share a single public IP address for Internet access. It helps conserve public IP addresses and improves network security.

Ransomware

Ransomware is a type of malicious software that encrypts a victim’s data and demands a ransom payment to restore access. It often spreads through phishing emails, malicious links, or infected downloads.

Firewall

A firewall is a network security system that monitors and controls incoming and outgoing traffic based on predefined security rules. It acts as a barrier between trusted internal networks and untrusted external networks.