Fish sauce is an ingredient that is used in many Thai and Asian dishes. It is made from a mixture of fish (typically anchovies), salt, and water which has then been fermented for a couple of months to 2 years. As implied by its name, fish sauce has a fishy taste but it is also slightly salty with a touch of sweetness. Despite anchovies being the most commonly used fish to create this sauce, on occasions, it may be made from mackerel or shrimp. To create the sweet flavoring, it is sometimes complemented with caramel or fried rice.
To make the fish sauce, the anchovies are put into a large barrel and then left to hang out. As the bacterias begin to break down the fish a briny, savory liquid is produced which we know as fish sauce.
Although the fish flavor of this sauce is only slightly noticeable when used in moderate amounts, if it is excessively used in dishes then the flavor is going to become much more apparent