@Pranav,

Since consumers pull from the partition, they are responsible for keeping the offset, a perfect analogy would be — Consider an array with data, we can have multiple process reading from this array, each keeping the corresponding last index they have read from.

I am planning to write many detailed blogs focussing on each of the Kafka gurantees. I have been quite lazy lately to plug my own learning gaps. There I will cover exactly-once delivary in detail.