Managed components
Note
Managed components are deprecated. A component is managed if it's a class, or a struct that contains managed (reference-type) fields. Both forms are deprecated. Use unmanaged components instead, and reference UnityEngine.Object instances with UnityObjectRef<T>.
A managed component is an IComponentData type that the runtime treats as managed: either a class, or a struct that contains managed (reference-type) fields such as string or other classes. Unlike unmanaged components, you can't access managed components in jobs or Burst compiled code, they require garbage collection, and they're more resource-intensive to store and access. Use unmanaged components instead.