If you're like many retirees, your Social Security checks will account for a large portion of your retirement income.

But how well you understand the ins and outs of these entitlements could make a big difference in how much you receive over your lifetime.

To that point, 69 percent of baby boomers — a generation of individuals who are either in or approaching retirement — expect Social Security to be a "major" source of retirement income, according to a new report released this month by the Insured Retirement Institute.

In contrast, just 28 percent of those surveyed expected employer pensions, the next source of major income, to provide a main chunk of their retirement pay.