A copywriter handles the copy aspect and does much of the conceptual thinking in press, television, outdoor, or any other form of advertising. A copywriter has to be very creative and good with words.
Along with the help of the visualiser and the creative/art director you'll create the advertisement as per the brief of the client servicing and research/planning department. You'll be an integral part of the creative planning process.
You have to create effective and memorable ads, which can catch the fancy of the target customers and make them buy the products. Once you prove your abilities you can rise from being a Junior copywriter to a senior copywriter, Copy Chief/Creative Supervisor and finally to the top - Creative Director.
Some requirements to be a good copywriter is that you should possess good (make that wild) imagination and ability to express it in an art form like writing poetry, writing stories, etc. You should have the ability to visualise concepts, to demonstrate concepts and ideas using the best possible words. You should have keen interest in various art forms like cinema, drama and music. Keep yourself in touch with the latest happenings in the world. An aptitude to understand how one behaves in a given situation or how one is likely to behave will hold you in good stead.
Copywriting is a creative job and as such you don't need a degree or diploma to enter this field. Most people in the advertising fraternity will tell you that they don't have an educational background in advertising. In fact people like Bharat Dhabolkar and Prahlad Kakkad never even planned a career in advertising - it just happened to them. The only qualification you need is creativity and no school will ever teach you that. Of course, if you have that creative streak in you, they will polish it for you.
Various institutes offer graduate, postgraduate and diploma courses in advertising and Mass Communication. You can even opt for a course in creative writing.