The difference is when it kicks it and for how long. Long-term disability insurance only kicks in after an elimination period (a.k.a. a waiting period). The typical elimination period is 90 days, but can be as long as 180 or 360 days depending on your policy.
A barn is an agricultural building usually located on farms and used for various purposes. In the North American area, a barn refers to structures that house livestock, including cattle and horses, as well as equipment and fodder, and often grain. As a result, the term barn is often qualified e.g. tobacco barn, dairy barn, sheep barn, potato barn.
A server farm is a set of many servers interconnected together and housed within the same physical facility. A server farm provides the combined computing power of many servers by simultaneously executing one or more applications or services. A server farm is generally a part of an enterprise data center or a component of supercomputer. A server farm is also known as a server cluster or computer ranch.