Research will sometimes be conducted by employees of the company that wants the information, and sometimes by third party suppliers. Companies who supply research to other companies are often called agencies (in North America, the term is less popular and they're often just called research companies or research suppliers. Generally the term 'supply side' is clearer / more globally recognised). Those who buy in other people's research (as well as doing their own) are often referred to as clients / clientside.
There are many different processes by which clients work with research suppliers, and the variety is growing rapidly as the choice of approach widens, the number of possible suppliers grows and business attitudes to old-fashioned client-supplier relationships change. It's perhaps useful to outline a traditional approach for a piece of custom research, and then detail some of the alternatives afterwards.
When a company decides to commission an agency / supplier to conduct research, it traditionally sends out a brief to a number of companies, who answer sometime later with a proposal of how they intend to carry out the work, together with costs. Agencies may then come in once or twice to discuss the proposals before one is chosen. Buyers sometimes have a preferred supplier in advance or are conducting a follow-on to another project and wish to use the same agency, in which case this stage would be abbreviated.
Briefs and proposals would discuss the client's business objectives, to ensure both parties understand fully what the research is for. Proposals set out in more or less detail how the agency proposes to go about the task: the information required, the source, the data collection method, the nature of the analysis and outputs that can be expected, and the timetable for the whole business.
Some agencies focus mostly on the data collection, often called fieldwork, and leave clients to do what they will with results (sometimes this is what clients want...) while others offer 'full service research', right through to helping clients implement whatever recommendations they have made based on their analysis.
A comprehensive guide to what we do, how it's changing, and who else does similar stuff.
The supply side: revenues, rankings and company info, full listings.