OTRS has a system of queues where tickets are delivered. Each queue can have a certain selection of tickets that they receive. The most common division of queues based on services that your company provides. The queues work automatically but tickets can be manually moved to other queues (e.g. faulty ticket, a solution requiring attention from the different department).
Every single registered entry is marked and receives its unique number forming a ticket.
Group of agents that can be assigned to different services (e.g. agent managing IT support may have no permission to open sales tickets and vice versa) can open a ticket and take responsibility to carry on conversation and keep your customer up to date with progress of the solution they need.
OTRS divides users into two categories – users that send their tickets to your system (e.g. customers) and agents who are your support employees.
Agents can be assigned to special groups, queues and roles which indicates how much responsibility each agent has and what kind of tickets are under his supervision.