Question about some code - Learning -

Greetings!

I would like to understand what the following code actually does?
string cmdText = "Select * from NAI_BusinessUnits";
SqlDataAdapter dataAdapter = new SqlDataAdapter(cmdText, conn);

dataAdapter.Fill(result, "NAI_BusinessUnits");
NAI.UI.PopulateDropDown(ddlCategories, result.Tables[0], new ListItem("Select One:"), "BusinessUnitName", "BusinessUnitID", "BusinessUnitID", true);
NAI.UI.PreSelectDropDown(ddlCategories, "Select One:", false);
 My question is related specifically to the following two lines:

1 - ...