Definition - What does Queries-per-Second (QPS) mean?
Queries per second is a measure of the rate of traffic going through a particular server in relation to a network that serves a Web domain. This measurement is important in assessing how support infrastructures handle changing amounts of Web traffic and whether systems are scalable enough to serve the changing needs of a user community as they grow.
Techopedia explains Queries-per-Second (QPS)
Looking at scalability and how servers handle changing workloads is part of understanding how the most successful Web services have evolved over time. Experts look at how services like Facebook and Twitter emerged from inconspicuous beginnings to become titans in the social media world. At the same time, tech companies are always assessing queries per second and other kinds of metrics in order to make sure that their systems are competitive and attractive to Web users.