Block Ciphers And Stream Ciphers: Block vs Stream Ciphers: DES, AES

Block ciphers and stream ciphers are two fundamental methods used in modern cryptography for encrypting data. Answer all of the following prompts:

Compare how each of these cipher types processes data and discuss the advantages and disadvantages of using block ciphers like DES and AES versus stream ciphers.
How does the structure of DES differ from that of AES, and why was AES chosen as a successor to DES?
Provide an overview of public-key cryptography and explain how it differs from symmetric encryption methods like DES and AES. Why is public-key cryptography important for secure communication in modern system?
Peer Reply Guidance:
Respond to at least two peers with substantive paragraphs.