What are hosted layers in the context of ArcGIS?

Hosted layers in the context of ArcGIS refer to layers that are managed by ArcGIS Online or Portal for easier collaboration. These layers are stored in the cloud, which enables users to access, share, and collaborate on geospatial data effortlessly across various devices and platforms. Hosted layers support a variety of data types, including feature layers, tile layers, and image layers, making them versatile for different applications.

The management by ArcGIS Online or Portal allows for centralized access, ensuring that users can efficiently work together on projects, making updates in real-time and leveraging the collaborative tools and capabilities that these platforms provide. This functionality enhances productivity and teamwork among users who may be working in different geographical locations.

In contrast to this, other options describe features that do not reflect the nature of hosted layers. For example, layers that can only be used offline do not benefit from the collaborative features of a cloud-based system. Similarly, traditional layers stored locally do not have the advantages of sharing and centralized management that hosted layers offer. Lastly, layers that cannot be shared with others contradict the fundamental purpose of hosted layers, which is to facilitate sharing and collaboration among users.