There is a three way relationship between Swiss Labour Contractors, yourself and the Contracting Company.

You have an employment contract with Swiss Labour Contractors. You become an employee of Swiss Labour Contractors with all the rights of an employee in terms of social protection such as accident insurance, pension, holiday pay, possibility to claim unemployment benefit. We ask you to sign a “convention de portage” and to respect a code of practice. You are responsible for finding your clients (Contracting Companies) and negotiating the rates.
Swiss Labour Contractors will ensure that all Swiss legal rules are complied with and obtain work permits where necessary. Social security and pension deductions are made from the salary with tax at source if applicable. A pension scheme is provided as well as accident insurance. In short you have all the social protection of an employee but with the advantages of self-employment.
The Contracting Company is responsible for providing your day to day work and supervision, whilst you are responsible for providing the work they want.
Swiss Labour Contractors and the Contracting Company have a service contract where Swiss Labour Contractors supplies you to the Contracting Company, and invoices your time (which is then paid to you as a salary).