Data Marts are a subset of a data warehouse that is tailored to the needs of a particular business unit or department. Data marts often contain data important to a specific business area, such as sales, marketing, or finance.

Online transaction processing (OLTP) is a type of database system used in transaction-oriented applications, such as many operational systems. “Online” refers to that such systems are expected to respond to user requests and process them in real-time.

ETL and ELT are two data integration methodologies that are used to extract data from different sources, transform it into a consistent format, and load it into a data warehouse or data lake.

OLAP systems typically store data in a multidimensional format, which allows users to slice and dice the data to see different relationships and trends.

Prescriptive Analytics helps explicitly link analysis to decision making by making recommendations on what we should do or what choice we should make to achieve a certain outcome. This analytical method involves integration of numerical optimisation techniques with business rules and even financial models.

Descriptive Analytics helps us describe what things look like or what happened in the past. It can take forms of simple aggregations or cross tabulations data.

Exploratory Data Analysis (EDA) is a statistical method that helps you understand your data by summarizing its most important features.

Data Warehouses are a central repository for data that has been merged from one or more diverse sources. Data warehouses are used to support BI activities like data mining, online analytical processing (OLAP), and business reporting.

Structured data and unstructured data are two types of data commonly used in the field of data science. The type of data that is used depends on the specific application.