Just to confuse everyone, there are two main kinds of planning application. The most common form is an application for full planning permission, where all the details of the design and location of the development are included. There is a standard application form available online – see www.planningportal.gov.uk Should a developer get approval, they may likely have to discharge conditions (set out by the planning authority) before they can commence development on a site.
The second kind of application is for outline permission. For this you only have to submit a redline boundary around land you wish to develop and an indicative description of the development being proposed. You do not have to submit details of design at this stage, although usually an indication of the scale and nature of the of the development is usually provided.
The purpose of outline applications is to test whether the principal of development on a particular site is acceptable, with all other matters (such as design, appearance, layout, landscaping and access) being considered at a later stage. Even if the application is approved in outline, there will then need to be a second reserved matters application which contains all the details of design and location.
It is worth bearing in mind that, once an outline application has been approved, it is usually quite rare for the full application to be refused on detailed issues.