We've talked about Artificial Intelligence (AI) as teaching computers to perform tasks that typically require human intelligence. A significant part of human intelligence involves understanding and using language. Think about how effortlessly you read this text, understand its meaning, ask questions, or write an email. For computers, this is incredibly challenging. Human language is complex, filled with nuance, context, and ambiguity.

This is where Natural Language Processing (NLP) comes in.

What is Natural Language Processing?

Natural Language Processing (NLP) is a specialized field within Artificial Intelligence focused specifically on enabling computers to understand, interpret, manipulate, and generate human language (like English, Spanish, or Mandarin) in a way that is valuable. It sits at the intersection of computer science, AI, and linguistics.

The goal of NLP is to bridge the gap between human communication and computer understanding. Instead of requiring humans to "speak computer" through rigid code or commands, NLP aims to allow computers to "understand human".

Why is NLP Important?

The ability for computers to process language unlocks countless possibilities:

Accessing Information: Search engines use NLP to understand your queries and find relevant web pages.
Communication: Machine translation tools break down language barriers. Chatbots provide customer support.
Automation: NLP can analyze large volumes of text data (like customer reviews or reports) much faster than humans.
Interaction: Voice assistants like Siri or Alexa rely heavily on NLP to understand spoken commands.

Common NLP Tasks

NLP encompasses a wide range of tasks designed to break down and work with language. Here are a few fundamental examples:

Text Classification: Assigning predefined categories to a piece of text. For instance, automatically labeling an email as "Spam" or "Not Spam," or determining if a movie review expresses a "Positive" or "Negative" sentiment.
Named Entity Recognition (NER): Identifying and categorizing specific entities in text, such as names of people, organizations, locations, dates, or monetary values. Finding "Apple Inc." and classifying it as an "Organization" in a news article is an example.
Machine Translation: Automatically translating text from one language to another, like translating an English sentence into French.
Question Answering: Providing answers to questions posed in natural language, often by searching through a given text document or knowledge base.
Text Generation: Creating new, coherent text. This can range from completing a sentence to writing entire articles or summaries. This particular task is a core capability of the Large Language Models we will be studying.

The Challenge of Human Language

Making computers understand language is difficult because human language is inherently complex:

Ambiguity: Words can have multiple meanings (e.g., "bank" can be a financial institution or a river edge). The surrounding text (context) is needed to figure out the intended meaning.
Context Dependence: The meaning of a sentence often depends heavily on the preceding sentences or the overall situation.
Variability: We express the same idea in many different ways (synonyms, sentence structures).
Informal Language: Slang, idioms, typos, and grammatical errors are common in real-world text.

NLP and Large Language Models

Historically, NLP systems often relied on complex sets of hand-crafted rules or statistical methods applied to smaller datasets. While effective for specific tasks, these approaches often struggled with the sheer complexity and nuance of language.

Large Language Models (LLMs) represent a major evolution in NLP. They use deep learning techniques and are trained on enormous amounts of text data. This allows them to develop a much more sophisticated grasp of language patterns, grammar, context, and even world knowledge, enabling them to perform a wide variety of NLP tasks, especially text generation and understanding, with remarkable fluency.

Think of NLP as the broader discipline, and LLMs as a powerful set of tools and techniques that have significantly advanced the capabilities within that discipline.

Relationship between AI, Machine Learning, NLP, and LLMs. LLMs are a specific type of model within the field of NLP, which itself is a part of Machine Learning and Artificial Intelligence.

Understanding the basics of NLP helps appreciate what LLMs are trying to achieve and why they are structured the way they are. We'll now look more closely at what defines a "Large Language Model."