Research contributes to practice by providing empirical information. Empirical information is information about the world as it is. Empirical information takes a variety of forms from qualitative to quantitative. Qualitative information is more in narrative than numerical form and is geared to providing intensive, in-depth information on what some aspect of reality subjectively means to people.
Qualitative information is especially useful for understanding subjective points of view.
Quantitative information is more numerical than narrative and is designed to provide extensive or generalizable information that objectively indicates what is happening across many people, cases, situations, etc. Quantitative information is particular useful for specifying broad patterns or trends across the populations being studied. Good social research, including social work research, need not be described as scientific. Science is often claimed to produce objective, factual, causal explanations of reality that are definitively true. No research probably ever does that.