Geographic Information Systems (GIS) — ArcGIS Online

ArcGIS Online (AGOL) is ESRI's web-based GIS software. You can use AGOL to create maps and interactive web applications; share content with stakeholders in your organization, and/or the general public; and access an expansive library of content from other users and organizations; among many other capabilities. In addition, AGOL also has spatial analysis capabilities. AGOL also communicates with ArcGIS pro, allowing you to publish and share ArcGIS pro projects online using the AGOL platform. 

AGOL uses a credit-based system for some types of functions, such as analysis, geocoding, and storage. This means that some of the functions of ArcGIS online will consume your available credits. The credit cost of certain functions is typically dependent on the number of records produced by the generated output. You can learn more about the credit system here.

One of the best things about web-based GIS systems like AGOL is the ability to easily share your maps and data, and access a vast library of maps and data from other users. Many reputable organizations, such as government entities, universities, international organizations, and GIS experts publish on ArcGIS Online and make their maps and data accessible and usable to everybody. But, anybody can publish to ArcGIS Online's content library! Check out this published and accessible map, for instance. 

When using maps and data published by someone else, ask yourself: 

• Do you know where this map/data is coming from? Who published it?
• Are you familiar with the organization/entity publishing this map? Is it a public or private entity?
• What are the objectives and mission of this entity?
• What information are they trying to communicate? Are they trying to prove a point or are they emphasizing a certain point of view?

A great place to look for this is in an item's details page:  

A comprehensive item details page should provide you with enough information to determine if the map/data you are looking at comes from a reputable source. You should be able to:

• Know who published this item, when it was published, and when it was last updated.
• See what data sources/layers were used in creating this map, and know where these data sources came from.
• Understand who the map is intended for, its intended use, and terms of use. 

Sharing your maps and data on ArcGIS Online

Sharing your projects is a great way to collaborate with stakeholders, communicate with the public, and add to the vast bredth of geospatial content available to other GIS users. When sharing your projects and data on ArcGIS online, be cognizant of the sharing level; you can make your project available to only you, other users affiliated with your organization, or publicly available. 

Be sure to fill out the item details page fully, and include:

• Any and all sources for your data and attriubution when necessary. 
• A description of your map.
• Terms of use.
• Publication date and update documentation.
• Item contact information.

This documentation from ESRI on configuring item details is a great place to start when documenting your item details.