Data mining is the process of automatically searching large volumes of data for patterns that match your criteria and then extracting that data from large databases. Think of it as an automated technique used to find relationships in large databases between 2 or more variables. The Data Mining Algorithms are the techniques or mathematical formulas used to get the results from the data. Here is a quote from Microsoft:
"Central to the data mining process, data mining algorithms determine how the cases for a data mining model are analyzed. Data mining model algorithms provide the decision - making capabilities needed to classify, segment, associate and analyze data for the processing of data mining columns that provide predictive, variance, or probability information about the case set... Many data mining algorithms are goal-oriented; given a case set, a data-mining algorithm will predict something about the case, usually an attribute of the case itself. Most algorithms require a training set of cases where the attributes to be predicted are already known, at which point the algorithm constructs a data mining model capable of predicting these attributes for cases in which the attributes are unknown".