How many types of research design?

Research design is the framework of research methods and techniques chosen by a researcher. Generally, there are mainly two types of research design: quantitative research design and qualitative research design. Quantitative research deals with numbers and statistics, while qualitative research deals with words and meanings. Each of these types of research has different objectives and methods, and both are important for gaining different kinds of knowledge. The choose of research design should be based on specific research questions.

Thx.

In general, there were three, namely sequential mixed methods, concurrent mixed methods as well as transformative mixed methods

There are different mixed methods about the research design. May I know how many of them?

The purpose of each design is as follows:
Qualitative research: To explore the meaning individuals or groups that lead to a social problem.
Quantitative research: To test the relationships among variables
Mixed method research: To gain more comprehensive understanding of a study by combining both qualitative research and quantitative forms.

I am not familiar with those. May you explain the purpose of each design?

Generally, there are 3 types of designs, which are qualitative research, quantitative research and mixed methods research.