_link> <span class=md-ellipsis> Key Concepts </span> </a> </li> <li class=md-nav__item> <a href=../../specification/terminology/ class=md-nav__link> <span class=md-ellipsis> Terminology </span> </a> </li> <li class=md-nav__item> <a href=../../specification/architecture/ class=md-nav__link> <span class=md-ellipsis> Architecture </span> </a> </li> <li class=md-nav__item> <a href=../../specification/core-components/ class=md-nav__link> <span class=md-ellipsis> Core Components </span> </a> </li> <li class=md-na