Hello Mpho,
ARP is a resolution protocol that allows to map an IP address to the corresponding MAC address your understanding is correct.
ARP by itself does not provide any form of redundancy, however the First Hop Redundancy Protocols like HSRP, VRRP and GLBP all work by answering to ARP requests for the configured default gateway.
The starting point of network redundancy is that each end user device is configured with a default gateway and as soon as it needs to send traffic to a destination outside the IP subnet to which it is connected the device will send out an ARP request to resolve the default gateway.
All the FHRP protocols work by having an active router answering the ARP requests for the default gateway with an appropriate virtual MAC address (protocol specific) and allowing at least for redundancy. If the active router fails another router takes its place and the identity of the default gateway at layer 2 (same VIP MAC address) and at layer 3 (same IPv4 VIP address).
GLBP is different in the fact that allows for redundancy and load balancing by default.
HSRP and GLBP are Cisco proprietary. VRRP is standard based.
So ARP is not by itself a mechanism that provides redundancy, but the way it works allowed for the introduction of protocols that introduce that redundancy for end user devices (PCs and workstations).
I see that in wikipedia CARP is described here
https://en.wikipedia.org/wiki/Common_Address_Redundancy_Protocol
I think it it can be considered an ancestor of VRRP and the other protocols described here.
To be frank I had never heard about CARP.
Hope to help
Giuseppe
