The Table Access Protocol: Providing standard access to astronomical data

In the upcoming era of large scale, geographically distributed, varied sources of astronomical data, a standard, simple and flexible way to access this data is necessary and useful for astronomers across the globe. Most of the modern surveys such as the Sloan Digital Sky Survey (SDSS) are available in well organized tabular formats. The Table Access Protocol (TAP) supports a standard web interface to access this kind of tabular data. Predefined queries and results formats help different data providers to implement these services. TAP also helps various software tools to access data and perform cross-matches seamlessly across different data sources. It is then possible to access data in tools that consume TAP web services. This supports further detailed data analysis on a queried slice of data. This document describes TAP and its utility for astronomers and data scientists. It also provides information on the protocol for data providers and developers.