This document provides an overview of big data architecture, the Hadoop ecosystem, and NoSQL databases. It discusses common big data use cases, characteristics, and tools. It describes the typical 3-tier traditional architecture compared to the big data architecture using Hadoop. Key components of Hadoop like HDFS, MapReduce, Hive, Pig, Avro/Thrift, HBase are explained. The document also discusses stream processing tools like Storm, Spark and real-time query with Impala. It notes how NoSQL databases can integrate with Hadoop/MapReduce for both batch and real-time processing.