An Ethical issue is a problem or issue that requires a person or organization to choose between alternatives that must be evaluated as right (ethical) or wrong (unethical). These issues must be addressed and resolved to have a positive influence in society.
Some of the common ethical issues are listed below:
(i) Cyber crime
(ii) Software Piracy
(iii) Unauthorized Access
(iv) Hacking
(v) Use of computers to commit fraud
(vi) Sabotage in the form of viruses.

Generally, the following guidelines should be observed by computer users:
(i) Honesty: Users should be truthful while using the internet.
(ii) Confidentiality: Users should not share any important information with unauthorized people.
(iii) Respect: Each user should respect the privacy of other users.
(iv) Professionalism: Each user should maintain professional conduct.
(v) Obey The Law: Users should strictly obey the cyber law in computer usage.
(vi) Responsibility: Each user should take ownership and responsibility for their actions.

A proxy server provides a gateway between users and the internet. It is a server, referred to as an “intermediary” because it goes between end-users and the web pages they visit online. A proxy server is essentially a computer on the internet that has an IP address of its own.

Encryption and decryption are processes that ensure confidentiality that only authorized persons can access the information.
Encryption is the process of translating the plain text data (plaintext) into random and mangled data (called cipher-text).
Decryption is the reverse process of converting the cipher-text back to plaintext. Encryption and decryption are done by cryptography. In cryptography a kev is a piece of information (parameter) that determines the functional output of a cryptographic algorithm.

A firewall is a computer network security based system that monitors and controls incoming and outgoing network traffic based on predefined security rules. A firewall commonly establishes a block between a trusted internal computer network and entrusted computer outside the network. They are generally categorized as network-based or host-based. Network based firewalls are positioned on the gateway computers of LANs [local area Network], WANS [Wide Area Network] and intranets.