This read-only Counter32 stores the raw value of the sampled counter recorded at the moment a given history bucket was taken. Admins care because this is literally the data point an NMS uses, diffed against the prior bucket, to compute throughput or error rates over that interval. For example, a bucket sampling an interface's octet counter returns the raw byte count at that snapshot, which graphing software subtracts from the previous bucket's value to derive average throughput.