MongoDB is a scalable, high-performance, open source, document-oriented database. MongoDB bridges the gap between key-value stores (which are fast and highly scalable) and traditional RDBMS systems (which provide rich queries and deep functionality).

Ruby is a dynamic, reflective, general purpose object-oriented programming language. Ruby is designed for programmer productivity and fun, following the principles of good user interface design.

Ruby on Rails, often shortened to Rails or RoR, is an open source web application framework for the Ruby programming language. It is intended to be used with an Agile development methodology that is used by web developers for rapid development.

Memcached is a general-purpose distributed memory caching system. It is often used to speed up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an external data source (such as a database or API) must be read.

The Amazon Web Services (AWS) are a collection of remote computing services (also called web services) that together make up a cloud computing platform, offered over the Internet by Amazon.com.

Apache Hadoop is a software framework that supports data-intensive distributed applications under a free license. It enables applications to work with thousands of nodes and petabytes of data.

MapReduce is a framework for processing huge datasets on certain kinds of distributable problems using a large number of computers (nodes), collectively referred to as a cluster.