On the general Host we operate with different applications
web browser, Telnet, FTP, email client (SMTP)
Protocols: HTTP, FTP, TFTP, Telnet, SNMP, DNS
PDU : Data
This website has an article about the on-board diagnostics system (OBD system) which turns on the Check Engine light in a motorized vehicle: https://motorist.org/articles/check-engine-light
Hope it helps you!
Modem provides internet, WiFi, we can connect multiple devices to internet through modem.
Modem provides radiation of short wavelength and the transmitter in your mobile phones and computers convert those radiations into digital signals and vice-versa.
D3+(A3-B3) If you think of the future income and expenses then you can infer the expenses will lower the income amount so we use parenthesis and since there is money already in the account you would simply add that to the future total. <span />
