This document discusses big data characteristics, issues, challenges, and technologies. It describes the key characteristics of big data as volume, velocity, variety, value, and complexity. It outlines issues related to these characteristics like data volume and velocity. Challenges of big data include privacy and security, data access and sharing, analytical challenges, human resources, and technical challenges around fault tolerance, scalability, data quality, and heterogeneous data. The document also discusses technologies used for big data like Hadoop, HDFS, and cloud computing and provides examples of big data projects.