The meaning of the Hebrew word mishpat is "judgment or rights." It can reference someone who sits to hear a case like a judge and who ultimately renders a verdict. In reference to the rights of someone (Exodus 23:6), there are several related meanings, according to Vine's. It can refer to the area in which things remain in a proper relationship to someone's claim (Genesis 18:19), a judicial verdict (Deuteronomy 17:9), and an established ordinance (Exodus 21:1).
Wilson's Word Studies makes an interesting comment about the word mishpât:
"There is a considerable difference between this word and [another Hebrew word], the former being much more general. Jeremiah 10:24, 'correct me, but with judgment,' as a just as well as a considerate judge. The latter rather implies a settlement of right between two persons, as to what is due to one or both; if Jeremiah had used this word, he would have prayed God to correct him according to his desserts [i.e., what he deserves]."
Examples of judgments concerning how to apply God's law concern the laws of inheritance when a man has only daughters (Numbers 27:1-11; 36:1-12). After this case with the daughters of Zelophehad, it then served to govern how similar cases should be decided in the future. In principle, this is rather like how English common law operates, in which prior decisions by judges should be normally respected by future judges as precedents to follow when making their own decisions in the same or analogous cases. The difference here, however, is that God made the initial decision when this case was brought to His attention, rather than a human judge trying to figure out what is just, according to tradition and human reason, when some novel or first-time problem is brought to his (or her) attention.
The Hebrew word translated "commandment," which is mitsvâh normally appears when God Himself directly gives the order in question. It isn't used often to refer to what human kings or others in authority order or tell others to do. The plural of mitsvâh often refers to a "body of laws" which are given by divine revelation, according to Vine's. According to Wilson's this Hebrew word means:
"to set up, to put, to place; to constitute, appoint; to command, to charge. . . . With an [accusative, or a word meaning "to" someone or something] of person, without mention of the thing commanded . . . " (p. 87)
An interesting comment by the (liberal) Interpreter's Commentary is that Deuteronomy 6:1-3 is (another) introduction to the law. Therefore, it makes sense it would mention the different parts or sections of God's law. The Shema, which starts in Deuteronomy 6:4, is so well known among Jews and informed Christians as virtually a "thesis" statement summarizing the core of Jewish belief.
I hope this brief answer has helped you understand the difference between God's commandments, judgments and statutes a little bit more.