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A Beginner's Glossary of Call Center Terms
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Call centers have a language of their own. New starters often hear unfamiliar terms in their first week, from AHT and ACW to IVR, ACD, and WFM, and it can feel like learning a new vocabulary on top of a new job. Even experienced professionals sometimes come across terms they've never heard, especially as AI and new technology add fresh jargon.
This glossary explains the most common call center terms in plain language. It's designed as a quick reference for anyone new to the industry, or anyone who wants to understand what's being discussed in meetings, reports, and training.
People and Roles
Agent (also advisor, representative, associate). The person who handles calls and other customer contacts.
Team leader (or supervisor). The person who manages a team of agents, coaching them, monitoring performance, and handling escalations.
Closer. In sales operations, an experienced salesperson who takes qualified calls and handles the final stage of the sale.
Subject matter expert (SME). A person with deep knowledge of a particular product, process, or topic, who helps colleagues with difficult questions.
Quality analyst. A person who reviews calls against quality standards and provides feedback.
Workforce planner. A person who forecasts call volumes and creates staff schedules.
Real-time analyst. A person who monitors call activity during the day and makes adjustments, such as moving breaks, to keep service on track.
Calls and Contacts
Inbound call. A call made by a customer to the business.
Outbound call. A call made by the business to a customer or prospect.
Blended. An operation or team that handles both inbound and outbound calls.
Contact. Any customer interaction, including calls, chats, emails, and messages.
Escalation. Passing a call to someone with more authority or expertise.
Warm transfer. A transfer where the agent speaks to the next person first and explains the situation before connecting the caller.
Cold transfer (blind transfer). A transfer where the call is passed on without speaking to the next person first.
Abandoned call. A call where the caller hangs up before reaching a person. In outbound calling, it also means a call answered by a person when no agent is available.
Callback. A call returned to a customer, often offered instead of waiting in a queue.
Wrap-up. The tasks an agent completes after a call ends, such as writing notes.
Performance Measures
AHT (average handle time). The average total time spent on a call, including talking, holds, and after-call work.
ASA (average speed of answer). The average time callers wait before their call is answered.
Service level. The percentage of calls answered within a target time, such as 80% within 20 seconds.
Abandonment rate. The percentage of callers who hang up before being answered.
FCR (first call resolution). The percentage of issues resolved on the first contact.
CSAT (customer satisfaction score). A measure of how satisfied customers were with an interaction.
NPS (Net Promoter Score). A measure of how likely customers are to recommend the business.
CES (customer effort score). A measure of how easy it was for customers to get what they needed.
Occupancy. The share of logged-in time agents spend actively handling contacts.
Utilization. The share of paid time agents spend logged in and working.
Schedule adherence. How closely agents follow their planned schedules.
Attrition (turnover). The rate at which staff leave.
Contact rate. In outbound calling, the share of dials that reach a live person.
Conversion rate. The share of contacts that result in the desired outcome, such as a sale or booking.
Technology
ACD (automatic call distribution). The system that queues and distributes incoming calls to available agents.
IVR (interactive voice response). An automated phone menu that callers interact with by pressing keys or speaking.
Dialer. Software that places outbound calls automatically or semi-automatically.
Predictive dialer. A dialer that dials ahead based on predictions of when agents will be free.
CTI (computer telephony integration). Technology that connects phone systems with computer systems, such as showing customer details when a call arrives.
CRM (customer relationship management). Software that stores customer information and interaction history.
Softphone. Software that lets a computer act as a phone.
VoIP (voice over internet protocol). Technology that carries voice calls over the internet.
SIP (session initiation protocol). The set of rules used to start, manage, and end internet-based calls.
SIP trunk. A virtual connection between a business phone system and the wider phone network.
DID (direct inward dialing). A phone number that routes directly to a specific person, team, or system.
Knowledge base. A searchable library of information agents use to answer questions.
WFM (workforce management). Software and processes used to forecast demand and schedule staff.
Quality and Coaching
QA (quality assurance). The process of reviewing calls to check they meet standards.
Scorecard. A checklist used to assess call quality.
Calibration. A session where reviewers score the same calls and compare results to ensure consistency.
Side-by-side coaching. Coaching delivered while sitting with, or virtually joining, an agent during live calls.
Whisper. A feature that lets a supervisor speak privately to an agent during a call without the customer hearing.
Barge. A feature that lets a supervisor join a live call so both agent and customer can hear them.
Nesting. A period after training when new agents take live calls with extra support.
AI and Automation
AI voice agent. Software that holds spoken phone conversations using AI.
Agent assist. AI tools that support agents during live calls, such as suggesting answers or writing notes.
Speech recognition (ASR). Technology that converts speech into text.
Text-to-speech (TTS). Technology that converts text into spoken audio.
Sentiment analysis. AI analysis that estimates the emotional tone of a conversation.
Speech analytics. Analysis of call recordings or transcripts to find patterns and insights.
Containment rate. The share of contacts fully handled by automation without needing a person.
Hand-off. Passing a call from AI to a person, or from one person to another.
Compliance
DNC (Do Not Call). Lists of numbers that shouldn't receive telemarketing calls.
Consent. Permission given by a person to be contacted in a certain way.
Disclosure. Information that must be given to callers, such as identifying the business or stating that a call is recorded.
PCI DSS. Security standards for handling payment card data.
Opt-out. A request by a person not to be contacted again.
Learning the Language
Like any industry, call centers use shorthand to communicate quickly. Once these terms become familiar, reports make more sense, meetings are easier to follow, and it becomes clearer how each part of the operation fits together. Many of these terms are explored in more depth in the other articles in this series.