These are terms that describe temporary states the military services can impose under which everything you thought you knew about your retirement date, your service exit date or your change of duty station date gets thrown out the window.
The Stop Loss as you may infer indicates servicemembers may not leave the service while in effect, regardless of the terms of their enlistment contracts.
Stop Movement is usually a tag along order that means servicemembers must remain with their current unit until the end of the Stop Movement period.
So what does that mean to you and me?
If your soldier belongs to the 1st Armor Division, for instance, and was scheduled to leave the service, retire, go off to the Sergeant Major's Academy, go off to the Officers Advanced Course or Advanced Non Commissioned Officers Course anytime between now and say, late July 2004...well, all indicators are that it won't happen.
For 1AD soldiers the best guess timeline right now is this: The 1AD redeploys (aka comes home) over the course of April and May. All soldiers currently assigned to 1AD will be required to remain with the 1AD until 90 days after redeployment. So...first moves/retirements/end of service dates are 90 days after April/May meaning July/August.
Here is what the Stars and Stripes has to say on the story. And here is the Washington Times Story.