What does 'Call-in' or Called-in Planning Application mean in a planning context?

The Secretary of State can “call in” certain planning applications that local authorities propose to approve. For example, where it may have wider effects beyond the immediate locality, significant regional or national controversy, or potential conflict with national policy. These will then be subject to a public inquiry presided over by a Planning Inspector who will make recommendation to the Secretary of State who will decide the application instead of the local planning authority.