A schedule of condition and a check-in report serve essentially the same purpose: they record what the property looked like at the start of your tenancy so that any changes can be measured against a clear baseline. The term "schedule of condition" is more commonly used in commercial property, but it appears in some residential tenancies as well, particularly when the property is being let in a less-than-perfect state.
Where a schedule of condition is provided, it typically acknowledges pre-existing issues and agrees that you won't be held responsible for them. This can be useful if the property has visible wear, older fixtures, or cosmetic issues that might otherwise be disputed at the end of the tenancy.
Whether you're given a schedule of condition, a check-in report, or nothing at all, the principle is the same: you need a detailed, timestamped record of the property's condition when you move in. If one is provided by the landlord, check it carefully and supplement it with your own photographs, or create your condition report.