An IP address serves two principal functions in networking: host identification and location addressing. The role of the IP address has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there." Although IP addresses are stored as binary numbers, they are usually displayed in a human-readable format, such as 192.168.1.100 (as for IPv4) or 2001:db8:0:1234:2:567:1:1 (as for IPv6).
ISP a.k.a Internet access provider (IAP) is a company which provides its customers access to the Internet. ISPs often offer many types of internet connections such as dial-up, ADSL, cable modem, or wireless.
DNS is an internet service which translates domain names into IP addresses. Domain names are alphabetic and easier to remember such as www.yahoo.com, www.google.com, or www.your-ip.com. However, these human-readable names don't do machines any good. Each domain name has its own unique IP address. A domain name server translates the human-readable domain name into the machine-readable IP address. For example, when google.com is entered in the browser, the DNS will translate the google.com into 18.104.22.168 and your browser will be able to browse at that specific IP address.
DHCP is a protocol for assigning dynamic IP addresses to devices on a network. A DHCP server leases out addresses for specific times to the various hosts. However, if a host does not use a given address for a certain time period, the IP address can be then assigned to another machine by the DHCP server