According to Wikipedia, "the internet is a computer network that links billions of computing devices all over the globe." [Citation needed] Using a "nuts and bolts" method to explain what they are, please provide a concise explanation of the following three components, as well as the role each of them plays in enabling communication through the internet:

Wireless LAN standard IEEE 802.11 has evolved throughout the last two and half decades. The security measures, Physical layer and MAC layers have been modified as per the need of the hour. 1.a) What are the MAC layer improvisation took place in the context of hidden node terminal and exposed node terminal since the first standard appeared, explain the problem with appropriate figures. (500 words minimum, add atleast two diagram) 1.b) Mention at least four latest issues which it (IEEE 802.11) needs to deal with while being incorporated with Internet of Things (IoT). 1.c) Describe CSMA/CA and CSMA/CD? Why CSMA/CD was not preferred over CSMA/CA for WLAN? Please adhere to the following guidelines for writing your summary: Your report should include at least two figures and/or tables. Do not forget to include a caption for each figure/table and to use cross-referencing. Ensure that your report meets the objectives, has an appropriate structure and…

Explain the purpose of the OSI (Open Systems Interconnection) model and its seven layers. What are some key responsibilities of each layer?

In what specific sense do you mean "computer network"? Are there any details that need to be kept in mind? What are the most important justifications for establishing a computer network?