In a nutshell, It is a system which tries to differentiate different time periods in the history (and future) of mankind. To make it easier to see different periods of time in a historical perspective. It divides history (or future) in ages, or as the Bible calls it, Dispensations.
Ie, The dispensation or age of Innocence. Separates the pre-sin period of time, so it can be differentiated from other periods of times. Or the age of Grace, which allows people to seperate things occurring in this age from the age of law. Which things happened differently.
It is not unlike taking a history book, where different ages were separated to help the student differentiate between different time periods or different dynasties.
And sadly, it is vehemently attacked by false truths, false ideas, and false representations of what it is, and what it means.
There are some vies of dispensation which are out there (ie people are saved by law. And will return to law) but those views are few and far between. But since they are there, People attack everyone who believes that way, and try's to put them all under that category.
Locutus is one of the worst offenders of doing this. They lie about Sofied (they claim he taught this different ways to heaven nonsense, which if they would actually study his writings and teaching, He does not, Scofield taught in all ages we are saved by grace. Period)
One example is the statment-->MANY are called but few chosen
Yet they will say MANY equals ALL and deny the fact that not ALL are not called!!