There are various ways structure can be defined to cover activities from pre-trade to post-trade.
One of the way is: Front Office; Middle Office; Back Office
Front Office: Is mostly client facing staff. This is where traders come into picture. If you have only business knowledge, this is the riskiest but most lucrative place to be in. Professionals having just business knowledge dream to move to front office directly or from back to middle to front office. Don’t get hurt by “just” word here. There is and always will be need of experts who know just business.
Middle office: Is mostly supporting staff. They ensure that compliance, research and process is followed. They also help traders with documentation stuff so that traders can focus on their trading job only.
Back office: Mostly manage the post trade activities and infrastructure (for complete trade life cycle). If you know only business, back office is least paid job, you will want to move to front office to have better pay. However, if you are good in few technical stuffs in addition to basics of business, back-office is highly lucrative job especially when combined with automation.