Temporary Spousal Support (also called "pendente lite") can be ordered paid after a petition for dissolution/separation is filed and usually terminated upon the entry of final judgment (when the judge makes your divorce official).
Temporary Spousal Support, though discretionary, is usually awarded without regards to the merits of the case and is generally determined by formula. For example, Placer County Local Rule 30.3 (B) (effective 7/01/11) says, "In cases where there is no child support, temporary spousal support will be 40% of the net income of the payor minus 50% of the net income of the payee." Whether you are in Sacramento, Placer, El Dorado or any other local county, our office has software to calculate how much temporary spousal support should be.
Permanant or long term support is generally just referred to as "spousal support" (it used to be called alimony) may not be permanent or may not be long term. Generally, "spousal support" will begin when a judgment for dissolution is ordered by the court. "Spousal Support" ends when the supported party gets married; either party dies, or upon further order of the court. "Spousal support" can be modified or terminated even after an original order is issued.