NLP (Natural Language Processing): definition and applications

François
Glossary
- 8 min reading
Published on
January 7, 2026

When you ask Siri for the weather or your chatbot understands your question, NLP is at work. This technology enables machines to understand and interact with human language.

In this guide, discover what NLP is, how it works, and its practical applications in customer service.

NLP: definition

Natural Language Processing (NLP) is a branch of artificial intelligence that enables machines to understand, interpret, and generate human language.

NLP bridges the gap between human language (ambiguous, contextual, full of nuances) and computer language (binary, logical, structured).

Thanks to NLP, you can:

  • Ask a voice assistant a question
  • Use an automatic translator
  • Receive suggested replies in Gmail
  • Interact with a chatbot

How NLP works

NLP breaks down language processing into several steps:

1. Tokenization

The text is divided into basic units: words, sub-words, or characters.

Example: "Hello, I would like a refund" → ["Hello", ",", "I", "would like", "a", "refund"]

2. Lexical analysis

Each word is identified: is it a verb, a noun, an adjective? What is its base form (lemma)?

3. Syntactic analysis

The structure of the sentence is analyzed: subject, verb, complement. How are the words connected to each other?

4. Semantic analysis

The meaning of the sentence is extracted. What does the text mean? What is the intention?

5. Pragmatic analysis

Context is taken into account. The same word can have different meanings depending on the situation.

The main tasks of NLP

Sentiment analysis

Determine whether a text expresses a positive, negative, or neutral sentiment. Very useful for analyzing customer reviews or detecting dissatisfied customers.

Text classification

Automatically categorize text: spam/non-spam, type of request, urgency, etc.

Named entity extraction (NER)

Identify key elements: names of people, companies, dates, amounts, order numbers, etc.

Automatic summary

Condense a long text while retaining the essential information.

Automatic translation

Convert text from one language to another.

Text generation

Produce coherent text based on instructions or context.

Question-Answer

Understanding a question and answering it based on a knowledge base.

NLP and customer service

NLP is at the heart of customer service transformation. Here are some practical applications:

1. Chatbots and virtual assistants

NLP enables chatbots to understand customer questions, even when phrased in unusual ways, and provide relevant answers.

2. Intelligent ticket routing

Automatic content analysis to route the ticket to the right team or agent, without manual intervention.

3. Detection of urgency and sentiment

Identify dissatisfied customers or urgent situations to prioritize handling.

4. Suggested answers

Provide pre-written responses or relevant FAQ articles to the agent.

5. Conversation analysis

Extract insights from thousands of conversations: recurring themes, emerging issues, opportunities for improvement.

6. Real-time translation

Enable a French agent to respond to a Spanish customer, with automatic translation on both sides.

Klark uses NLP to analyze each request, understand the customer's intent, and instantly provide the best response.

NLP techniques

Traditional approaches (rules)

Manually defined rules: "if the message contains 'refund' then categorize it as 'Billing'."

Advantages: precise within a defined scope, explainable.

Limitations: rigid, does not handle variations, heavy maintenance.

Traditional Machine Learning

Algorithms learn patterns from examples: Naive Bayes, SVM, Random Forest.

Advantages: more flexible than rules, learning from your data.

Limitations: requires labeled data, limited performance on complex language.

Deep Learning and Transformers

Deep neural networks, particularly the Transformer architecture (the basis of LLMs), have revolutionized NLP.

Advantages: exceptional performance, understands nuances and context.

Limitations: requires computing power, less explainable.

NLP vs NLU vs NLG

Three similar but distinct acronyms:

TermMeaningFocus
NLPNatural Language ProcessingGeneric term, language processing
NLUNatural Language UnderstandingUnderstanding meaning, intention
NLGNatural Language GenerationGenerate coherent text

NLP encompasses NLU and NLG. A chatbot uses NLU to understand the question and NLG to formulate the response.

The challenges of NLP

Ambiguity

"I'm going to see my mother at the bank" → financial bank or school of fish? Context is essential.

Idiomatic expressions

"It's raining cats and dogs" doesn't really refer to cats and dogs. Figurative expressions are challenging.

Multilingualism

Every language has its rules, exceptions, and subtleties. NLP must adapt.

Informal language

Spelling mistakes, abbreviations ("hi," "pls"), emojis... Real language is far from perfect.

The context

"It's cold" can be a complaint or a simple observation depending on the context of the conversation.

Implementing NLP in customer service

1. Define your use cases

Automatic categorization? Sentiment detection? Chatbot? Start with a specific case.

2. Prepare your data

NLP needs data to learn. Your historical tickets are a gold mine.

3. Choose the right approach

Rules for simple and stable cases, ML/Deep Learning for complex and variable cases.

4. Test and iterate

NLP is never perfect the first time around. Measure, identify errors, improve.

5. Keep people in the loop

For ambiguous or sensitive cases, always allow for human intervention.

Frequently Asked Questions

What is the difference between NLP and AI?

NLP is a branch of AI that specializes in language processing. AI is the broader field that also includes computer vision, robotics, etc.

Does NLP really understand language?

It simulates understanding by identifying statistical patterns. It is not "true" understanding like a human, but it is often sufficient for practical applications.

Does NLP require a lot of data?

It depends on the approach. Pre-trained models (LLMs) work with little specific data. Custom models require more training data.

Does NLP work in French?

Yes, but historically, English models perform better. The situation is improving with multilingual models and French initiatives (CamemBERT, Mistral).

Conclusion

NLP (Natural Language Processing) is the technology that enables machines to understand and communicate with humans. For customer service, it is a major driver of automation and experience improvement.

The keys to using NLP effectively:

  • Start with a specific use case
  • Leverage your conversational data
  • Combine rules and ML depending on complexity
  • Measure and iterate continuously
  • Keep humans for sensitive cases

Want to leverage NLP in your customer service? Discover how Klark can help you.

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