A data analyst is a professional who uses analytical and statistical methods to collect, transform, and interpret complex data sets. They work with large volumes of data to identify patterns, trends, and insights that can help businesses make informed decisions.

The responsibilities of a data analyst may include:

1. Collecting and processing large datasets from various sources
2. Cleaning and transforming data to prepare it for analysis.
3. Conducting statistical analysis and creating visualizations to identify patterns and trends.
4. Developing predictive models and forecasting future trends
5. Creating reports and dashboards to communicate findings to stakeholders.
6. Identifying opportunities for process improvement and making recommendations to improve business performance.
7. Collaborating with other members of the organization to identify areas where data analysis can add value.

A successful data analyst should have a strong understanding of data analysis tools and techniques, including programming languages such as SQL, Python or R, as well as data visualization tools like Tableau or Power BI. They should also have excellent communication and problem-solving skills, as well as a deep understanding of the business and industry they work in.