1. The document defines key research-related terms like abstract, applied research, basic research, case study, causal comparative research, census survey, cluster sampling, content analysis, control, control group, and continuous variable. 2. It also explains research types like correlational research, descriptive statistics, document analysis, ethnographies, experimental research, historical research, observational research, qualitative research, and quantitative research. 3. Additionally, it covers critical concepts like hypothesis, independent and dependent variables, limitation, meta-analysis, population, problem statement, purposive sampling, reliability, research plan, sampling, and validity.