Waiting for multiple concurrent things to complete isn't parallelism, in the on-topic jargon meaning of the term. Parallelism is things physically being execut

Waiting for multiple concurrent things to complete isn't parallelism, in the on-topic jargon meaning of the term. Parallelism is things physically being executed simultaneously, increasing throughput via physically multiple resources. The multiple IOs you're waiting on might be executing in parallel if you have e.g. a RAID array or SAN in the loop, but it's an implementation detail and isn't what the article is about.