Although there are numerous NLP tasks that can be performed, we will focus only on a subset of these tasks. A brief overview of these tasks is presented here, which is also reflected in the following chapters:

• Chapter 2, Finding Parts of Text
• Chapter 3, Finding Sentences
• Chapter 4, Finding People and Things
• Chapter 5, Detecting Parts-of-Speech
• Chapter 8, Classifying Text and Documents
• Chapter 10, Using Parsers to Extract Relationships 
• Chapter 11, Combined Approaches

Many of these tasks are used together with other tasks to achieve an objective. We will see this as we progress through the book. For example, tokenization is frequently used as an initial step in many of the other tasks. It is a fundamental and basic step.