Hi Alphabrace,
As stated above there are less likenesses than there are differences. However what I think you are looking for is this:
The 1911 whether made by S&W or any other manufacturer is basically the same. They are Single Action only pistols, that is to say the the hammer must be cocked before the pistol can be fired. They also have multiple safety levers that must be disengaged before it can fire. The first is a grip safety that is released when you grasp the pistol. The second is a manual lever on the side of the pistol near the rear of the slide. This safety is a toggle safety that is either on or off. You may have heard the term Cocked and Locked, this is carrying a 1911 style gun with the hammer cocked and the safety at the rear of the slide engaged.
The other pistols manufactured by S&W are different types of actions, the ones that come to mind are the Traditional Double Action (TDA) where the first round is fired Double Action, that is long heavy trigger pull much like a revolver. Subsequent shots will be fired Single Action, that again is with the hammer cocked and short light trigger pull. Pistols such as this are the 457 & 4506 that you see mentioned on the forum. These pistols are made in a number of different barrel lengths and size. These pistols have what is referred to as a Safety/Decocker. When the safety is engaged it safely drops the hammer on a live round. This type of pistol can NOT be carried "Cocked & Locked". It must be carried with the hammer down to be safe.
Other variants of the S&W pistol are like the 457 & 4506 except they may be Double Action only (DAO). This is just like a revolver where each pull of the trigger is the same long heavy trigger pull. These pistols traditionally don't have safeties since once you rack the slide the hammer falls safely on a live round.
Basically the difference is the mechanism of how the pistol functions. Please take time to learn the safety features of any pistol before you attempt to shoot them.
Hope this helps, Cheers,
Sam