# Key concepts

Most of Diarybook comes down to a few ideas: **clients** see **users** at **appointments**, and
**reminder settings** decide how clients are reminded. Everything else refines those four.

## People

| Term | Meaning |
|------|---------|
| client | The person an appointment is for, and who receives reminders. An appointment needs at least one client. See [Adding and Editing Clients](/docs/clients/adding-and-editing-clients/). |
| user | Someone with a sign-in to the Diarybook account. Users are managed in the **Users** area. See [Users and Permissions](/docs/setting-up/users-and-permissions/). |
| Can Take Appointments | A permission on the user record. Only users with it can be chosen as the person the client is to see. Turning it on also turns on **Can Use Schedules**. These docs call such a user a **service provider**. |
| department | An optional grouping of users and appointment types, used for reporting and for sharing access to colleagues' appointments. See [Departments](/docs/setting-up/departments/). |
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## Appointments

| Term | Meaning |
|------|---------|
| appointment | A booking of one or more clients with one or more users, at a date, time and duration. See [Adding an Appointment](/docs/appointments/adding-an-appointment/). |
| appointment type | What the appointment is for. Picking a type fills in its duration and, if the type has them, its waiting room, reminder setting and location. See [Appointment Types](/docs/appointments/appointment-types/). |
| confirmation status | Whether the client has said they are coming: **No Status**, **Confirmed**, **Unable To Attend (UTA)**, **Cancelled By Client**, **Cancelled By User** or **Tentative**. Client replies can set it automatically. |
| attendance status | What happened on the day, for example **Finished**, **DNA** or **Was Contacted**. See [Attendance and DNA](/docs/appointments/attendance-and-dna/). |
| DNA | Did Not Attend: an attendance status recording that the client didn't come to the appointment. |
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## Messaging

| Term | Meaning |
|------|---------|
| reminder setting | A named set of rules for when and how a client is reminded: which channels (SMS, email, voice, letter), on what schedule, and with what text. Each appointment uses one. See [How Reminders Work](/docs/reminders/how-reminders-work/). |
| sender ID | The name an SMS appears to come from, used when clients can't reply. It must be approved before it can be used. See [Sender IDs](/docs/setting-up/sender-ids/). |
| merge field | A placeholder such as `^^time^^` in message text, replaced with the appointment's details when the message is sent. See [Merge Fields](/docs/reminders/merge-fields/). |
| clinic code | For accounts synced with another system: the code on each incoming appointment that decides its user, appointment type and reminder setting. Set up under **Settings** → **Automatic Syncing**. See [Integration Overview](/docs/integrations/integration-overview/). |
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## Places, time and capacity

| Term | Meaning |
|------|---------|
| location | A physical site. Choosing a location on an appointment narrows the appointment types and resources on offer, and its details can go into reminders. See [Locations](/docs/setting-up/locations/). |
| resource | A room, piece of equipment or person booked alongside an appointment so nobody double-books it. See [Resources](/docs/setting-up/appointment-resources/). |
| waiting room | Where a client waits on the day. It can also limit how many appointments share the room. See [Waiting Rooms](/docs/setting-up/waiting-rooms/). |
| work hours | The hours a user is willing to take appointments in. Each user sets their own. See [Work Hours](/docs/your-user-profile/work-hours/). |
| schedule | A record of when one or more users are unavailable, such as leave or a weekly meeting. See [Schedules](/docs/setting-up/schedules/). |
| waiting list | A list of clients waiting to be seen, with priority and breach dates. See [Waiting Lists](/docs/waiting-lists/). |
| account policy | An account-wide rule that only the account owner can change, for example making waiting rooms mandatory on appointments. See [Policies](/docs/setting-up/policies/). |
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## Related

- [What Diarybook Does](/docs/start-here/what-diarybook-does/)
- [Your First Week](/docs/start-here/your-first-week/)

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Source: https://diarybook.com/docs/start-here/key-concepts/