Please explain each instruction with comment

What allows you to create a wireless connection among your smart devices

When you type the pwd command, you notice that your current location on the linux filesystem is the /usr/local directory. answer the following questions, assuming that your current directory is /usr/local for each question. a. which command could you use to change to the /usr directory using an absolute pathname? b. which command could you use to change to the /usr directory using a relative pathname? c. which command could you use to change to the /usr/local/share/info directory using an absolute pathname? d. which command could you use to change to the /usr/local/share/info directory using a relative pathname? e. which command could you use to change to the /etc directory using an absolute pathname? f. which command could you use to change to the /etc directory using a relative pathname?

When replacing a thermostat or water pump, coolant drained from the cooling system should be