I had to look up reconstructionist, and I am Jewish. I never heard of it before. Seems to be a fairly new movement, I don’t know much about it.
The others I can elaborate on, I have them listed from the most liberal to the strictist. As a side note, I recommend you don’t use the word conservative to describe Orthodox Jews as @Adirondackwannabe did (not being critical @Adirondackwannabe :)) because there actually are Conservative Jews and it can be confusing. Better to use the word observant rather than conservative.
Reformed: Jewish people who are not religious at all, but basically identify as Jews ethnically or culturally when asked what type of Jew they are will answer Reformed. You have probably noticed a lot of them here on fluther. We are Jewish, some of us Atheists. Reformed Jews usually do not follow the Kosher rules at all. Some Reformed Jews do nothing religiously, but many at least celebrate the holidays. They celebrate the holidays to different degrees. Like, in my family we used to do Passover Seder, but we did not eat unlevened bread for all the days of Passover. Some reformed Jews do go to temple every week, do all the major holidays, send their children to Hebrew school, and have their children go through barmitzvahs and batmitzvahs.
Conservative: Generally conservatives keep a Jewish home, meaning their kitchen is Kosher. Some celebrate the sabbath, some don’t. Some eat anything they want when outside of their home, some eat everything except pork and shelfish. They kind of pick and choose what feels right. Some think it sounds very hypocritical, but keeping a Jewish home in my opinion makes sense, because for me personally, the home and family is where I am most Jewish. Not that I am conservative, I’m reformed, I am only saying I can understand the reasoning.
Orthodox: Many Orthodox also refer to themselves as observant. They observe all the holidays (many reformed Jews don’t even know all the holidays, I had never heard of Purim untill I was in my 20’s) they observe the sabbath very strictly. They keep Kosher all the time. I knew a few Orthodox Jews who would cheat when out, but they would only eat fish and otherwise vegetarian. No chicken, beef, pork, lamb, or shelfish, etc., when outside their own home, unless they were in another kosher home or kosher restaurant. The Orthodox have a very tight community. They must live within walking distance of the synagogue, because they cannot drive on the Sabbath. They dress very modestly, women usually wear very long skirts, shirts are up to their neck, clothing should not be too tight. The married women wear wigs or hats, because their hair should not be seen by others, it is ok in front of their husbands and children and other women. There are different sects among the Orthodox, Chassidic, modern Orthodox, etc. Orthodox men always have their heads covered when outside of their home with a yarmulke or hat.