Without going too deep in the matter, I would like to try to explain this.
An IP address (also called an Internet address) is assigned in a home, garden and Kitchen network by the DHCP server in the router to each network host.A host is e.g. A router, computer, laptop, smartphone or a printer.
Each network host must have a network adapter to connect to the network.This can be done by cable or wireless.
Although the user can capture a network adapter a certain IP address, this is generally not necessary.To do this, the DHCP server that is using the MAC address (see below) assigns each network adapter a specific IP address that will not change for a certain time (lease time). More about this: Dynamic Host Configuration Protocol-Wikipedia
However a MAC address (also called Physical address) is fixed in the electronics of the network card.It is a unique address that gets any network adapter from the adapter manufacturer. Typically, the first digits of this number are a code that identifies the manufacturer. More about this: MAC address-Wikipedia
Because each network device (router, WiFi adapter, network adapter in computer, laptop, smartphone and printer) has a unique number, for example, a manufacturer can use this MAC number as the ID number in their customer base.
Since in an IP packet also the MAC address is present, the source (say the individual who sent this the Internet…) of this package can be obsolete by agencies and also hackers.
The above does not explain why you can not only work with MAC addresses.Here is a comment about this, and so I also add my reply in my original text:
Of course, it is too far to explain the entire IP address system here, but I would like to give one of the reasons why you cannot work with MAC addresses alone.
In contrast to a MAC address, an IP address is a hierarchical, binary system.See also: Hierarchical Addressing
The entire Internet system is built around routers.These nodes have a list of IP addresses that are in their “own” network. If a packet is passed, the router will be able to determine whether this packet should be sent to its network or not, on the basis of the IP address. This is therefore a binary system consisting of the simple decision whether or not the package is to be sent to the own network. Should only be worked with MAC addresses, each router should know all the MAC addresses in the world to make the decision where to send the package. This is of course impossible.
It is similar to mailing addresses or phone numbers and global BSN numbers.If you Stop a letter that needs to be sent to Japan in the Netherlands in a letterbox with an address written in Japanese letters, the Dutch post official cannot read this of course. But he does read the word Japan in plain letters that is at the bottom. He knows where it should be sent. In Japan, the Japanese post office can read where it is to be sent exactly.
Even if the parcel is sent to a specific address in the Netherlands, this is easy to realise with City, street and house number.Even if the street name and house number in other cities are also used, the address is unique by adding the city. If, as is often customary in America, many cities have the same name, the address is still unique because the name of the state is also mentioned for the city name.
Should be worked with global BSN numbers, a full list of every BSN number in the world would have to be in each post office in order to send the parcel or letter to the correct country, after which in that country in each post office this gigantic list should be In order to eventually transport it to the correct end address.An impossible thing! Thousands of new MAC addresses arrive every day, so every MAC list must be updated in every router in the world. Unstarted work….
The question “Why we have two addresses at the same time” contains a misconception that the addresses are used at the same time.
The story starts with the MAC address which is stored in any device (with the ability to network via the networking card or adapter) so that no device is the same. [nowadays often found on the barcode label
A network capable device therefore always has a MAC address but without IP connection no IP address.
When the device is connected and turned on to an Internet protocol (IP) network, a different device to this device often gives an IP address somewhere in that network.So that the first (MAC-containing) device can be reached via the IP address.
That other device can be at your home (local network) or your ISP.And that can connect with wire (fixed connection) or wireless.
But every time you disconnect and restore you can get another or the same IP address.This also happens when you turn off your device and turn it on. Or (wirelessly) if you hit and return out of reach of your network.
Conclusion: Only during the active “networks” the devices use an IP address.
[Thanks to Jack Klaber for explaining the technical terms
Very simple: MAC is used on Layer 2 (data link), for rudimentary local physical connections, IP on Layer 3 (network), to create networks and to enable routing, communication between networks, often at a longer distance.ARP is the protocol that captures the connection between a MAC address and an IP address.