Let's take a closer look at what standards are and why they're so important when you are designing your GIS solution.
The term standard as mentioned in Wikipedia (http://en.wikipedia.org/wiki/Technical_standard) may be explained as follows:
"An established norm or requirement in regard to technical systems. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes and practices. In contrast, a custom, convention, company product, corporate standard, etc. that becomes generally accepted and dominant is often called a de facto standard."
Obviously, a lot of standards exist if you consider the Information Technology domain. Standards are usually formalized by standards organization, which usually involves several members from different areas, such as government agencies, private companies, education, and so on.
In the GIS world, an authoritative organization is the Open Geospatial Consortium (OGC), which you may find often cited in this book in many links to the reference information.
In recent years, OGC has been publishing several standards that cover the interaction of the GIS system and details on how data is transferred from one software to another. We'll focus on three of them that are widely used and particularly important for GeoServer and ArcGIS for Server:
WMS: This is the acronym for Web Mapping Service. This standard describes how a server should publish data for mapping purposes, which is a static representation of data.
WFS: This is the acronym for Web Feature Service. This standard describes the details of publishing data for feature streaming to a client.
WCS: This is the acronym for Web Coverage Service. This standard describes the details of publishing data for raster data streaming to a client. It's the equivalent of WFS applied to raster data.
Now let's dive into these three standards. We'll explore the similarities and differences among GeoServer and ArcGIS for Server.