What does the 4 commandment mean?

Assuming that the question is referring to the Ten Commandments of the Hebraic and Christian religious beliefs, first one must decide something: which commandment is the fourth?

Over time different people have "numbered" the Ten Commandments differently. In this case, some groups would say that the fourth commandment is referring to "honoring the Sabbath and keeping it holy." Some groups would say that "honor your father and mother" is the fourth.

Because it seems that a command to honor one's parents is fairly easily understood and explained, this answer will assume that the question pertains to "honoring the Sabbath and keeping it holy."

As an interesting side note, this commandment is quite possibly the least honored in modern times. Though there are many non-Judeo-Christian cultures that punish stealing, murder and false testimony (and of course it is easy to understand why a god would say "worship me only") there are many modern Christians who don't understand or honor the Sabbath commandment.

Here are the most common ways it is viewed:

In any text, if one want to understand something it's best to look at all the text surrounding the piece in question. Interestingly, God has the most "extra" text to say about this commandment as compare to the others.

The text says that the humans are supposed to "work for six days" but "the seventh day is a sabbath to the Lord your God. On it you shall not do any work... For in six days the Lord made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the Lord blessed the Sabbath day and made it holy." (Exodus 20:8-11).

There is the first answer: God modeled a way of doing things that He wished for His people to follow. He made all things in six days and rested on the seventh, and wished for His people to do the same. This is probably more for the benefit of the human than for God.

Second, the human way of living tends to become busy and distracted. Many modern believers think that it is important to take a day not only to rest but to spend it with God. It's one day to remember blessings, to praise God for the chance to rest and to spend it building relationships with other believers.

Finally, I would personally venture this thought on the Sabbath: originally, according to scripture, God created an ideal world for man to live in with no death and with no toil. In Genesis, one of the things God warns mankind of as a consequence for the entry of sin into the world is that nothing will come easily anymore and that man would have to labor and toil over the ground to get it to produce food (Genesis 3:17-19).

Though much of scripture is concerned with the pain and consequences of the battle with sin that consumes human existence, it always has a note of hope and peace for God's children. I.e. He not only warns of sin's consequences but always offers a promise for freedom from it.

This is the final way to see the Sabbath: though God warns of all the work man will have to endure in order to survive He includes a reminder of rest from it. He includes provision for remembering that there is peace and hope in the midst of all the work and toil. Interestingly, God did not "sentence" the humans to endless labor and painful work after the first sin, but He merely informs them that they'll have to work at least as much as He did. He worked for six days and rested one and, rather than punishing mankind with terrible forced labor, they merely have to do as God did to get the food they need.