The relationship between data mining, text mining, and sentiment analysis is related to concepts in language processing and data analysis. They can be used for a specific purpose or together, depending on your desired outcome.

Data mining is for discovering patterns and trends within large datasets by using statistical, machine$-$learning techniques. Industries in finance and healthcare use this type of data analysis.

Text mining $($aka text analytics$)$ is the process of extracting meaningful information from unstructured textual data. Industries can use text mining techniques to analyze discussion boards and feedback, extract the desired information to address desired outcomes.

Sentiment Analysis is a sub$-$field of text mining, it focuses on the emotion behind the textual data. It can be used along with text mining or stand$-$alone. Industries that want to know how to keep customer dissatisfaction down will often use this type of analysis.