Glass.Mapper.Sc is different to other Sitecore Item abstractions that are available. Glass.Mapper.Sc is a mapping solution and not a wrapping solution.
In a mapping solution the data is read from the Sitecore Item and then written to the property on your model. In a wrapping solution the model property reads and writes directly to the underlying Sitecore Item. The difference is clear when you look at the code typical class.
A typical mapping model:
A typical wrapping model:
The first thing that is clear, is that there is a huge difference in the amount of code that you have to write for wrapping solutions. Typically most wrapping solutions will require some form of code generation where as a mapping solution allows you to choose between hand writing your models or using code generation.
A mapping solution also disconnects the model from the underlying item. This means that you can alter the properties on your model without affecting the underlying Sitecore Item. For example consider the following code that might be in a controller that uses a mapping solution:
Using a wrapping solution it isn't possible to write this type of logic safely because it requires putting the underlying Sitecore item into an editing state.
Let's look at the Pros and Cons of each solution.