The use of the term legacy in the IT world relates to software or hardware that has been superseded but is difficult to replace.
Typically legacy systems are hard to replace because they have been used for mission critical applications, so replicating them can be extremely time consuming and difficult, while there is also the risk of downtime, which is not appealing to businesses as it can seriously affect their operations.
Legacy applications and data are those that have been inherited from languages, platforms, and techniques earlier than current technology.
Changing it to newer technologies allows the business to use more efficient code in order to enable programmers to do more.
Programmers use to often write for specific manufacturers’ operating systems but now with many organisations migrating to new programming languages and operating systems, this has changed.
With newer systems programmers should be able to update applications without the need to entirely rewrite them.
Often the decision to migrate comes down to a matter of cost, whether it is more costly maintain than it is to migrate.
