Co-existence
Co-existence is the degree to which a product can perform its required functions efficiently while sharing a common environment and resources with other products, without any detrimental impact on those other products. It is a quality attribute and, per ISO/IEC 25010, a sub-characteristic of compatibility.
In practice, co-existence matters whenever multiple independent systems run on the same host, network, or platform. For example, several applications sharing a server’s CPU, memory, or disk, or several services competing for the same downstream dependency. A system with good co-existence degrades gracefully under that kind of contention, rather than starving its neighbors of resources.