Database types and definitions

This weeks blog task has two parts:

1. What is a database? In our own words, describe what we think a database is.
2. What are the different types of databases? Give examples of the different types of databases.

Wikipedia describes a database as:

A database is an integrated collection of logically related records or files which consolidates records into a common pool of data records that provides data for many applications.

If I was putting this in to my own words, I would describe it as a collection of information that is structured in such a way that any relevant information is easily accessible.

The second question is open to a bit of interpretaion. Many of the answers in the class had things like MySQL, Oracle, Access, SqlServer. According to WikiAnswers, the different types of databases are, "Hierarchical, Network, Relational, Object Relational".