Birch wood is usually creamy white to golden brown, depending on the particular species of tree and the part of the tree from which the wood came. The heartwood, toward the center of the tree, is darker than the outer sapwood. Birch is common in furniture construction and carpentry for several reasons: Its fine, uniform texture makes it easy to shape and tool; it doesn't warp if properly dried; and it's relatively inexpensive. Since so much furniture is made of solid birch, manufacturers of less-expensive furniture seek to mimic the birch look with effects and veneers.
IKEA, a manufacturer of inexpensive home furnishings that consumers must assemble themselves, popularized the term "birch effect." It refers to furniture that merely looks as if it's made of birch. This furniture is typically made of panels of fiberboard laminated with a top layer of plastic or heavy-duty paper printed with an image of birch wood grain.
Birch veneer is real wood -- but only a thin piece of it. Birch veneer furniture may be made mostly of fiberboard or plywood, with an outer later of real birch a fraction of an inch think. To the eye and the touch, it appears to be solid birch.
Both effects and veneers are cheaper than solid birch, which is why furniture makers and cabinetry makers use them. Since birch veneer is truly wood, it not only feels more authentic, but it also can be stained and finished like solid wood. With birch effect, neither is possible; if you want to change the look, you'll have to paint it. On the other hand, since birch effect has no grain to absorb moisture, it's more water-resistant than veneer -- although if the thin "effect" layer has been punctured, water can seep into the fiberboard underneath and cause it to swell, creating bubbles in the effect layer.