Difference between sum_irate and sum(rate())?

I uses two metrics node_namespace_pod_container:container_cpu_usage_seconds_total:sum_irate and container_cpu_usage_seconds_total with the sum, rate function

sum_irate

node_namespace_pod_container:container_cpu_usage_seconds_total:sum_irate{namespace="$namespace", pod=~"$PodPrefix-.*", container!=""}

sum(rate())

sum(rate(container_cpu_usage_seconds_total{namespace="$namespace", pod=~"$PodPrefix-.*", container!=""}[1m])) by (pod)

These show different values.
Also, both shows exceed 100% CPU Util.

I wonder what is difference between them.

I expected two metric result in same value.
But it’s different.

container_cpu_usage_seconds_total:sum_irate was higher than sum(rate(container_cpu_usage_seconds_total))[1m]

And sum(rate(container_cpu_usage_seconds_total))[1m] is higher than the sum(rate(container_cpu_usage_seconds_total))[5m]