A CV covers your education, work experience and skills and should be targeted towards a particular job, along with a relevant covering letter.
It is a good idea, however, to keep a full CV that has details of all your qualifications and experience as a master CV from which to draw upon for each individual application. Remember also to keep all the relevant certificates that prove your qualifications.
An application form is often used by major employers and is increasingly completed online. The major difference is that you have to complete the allocated boxes and you may also be asked to give real examples to demonstrate your ability in certain skills.
Bear in mind that if an employer wants a completed application form, that is what you should submit. Include a covering letter, but not a CV.
The CivvyStreet CV Builder and Tools helps you to create a CV by entering information about yourself online.