# Providers & Services — NestJS

Source: https://www.geekswithgeeks.com/en/nestjs/nestjs-providers-services

> Services encapsulate business logic; providers are registered in modules.

## Anatomy of a service

A service is a class with `@Injectable()` that holds your business logic—fetching data, validating rules, etc.

```typescript
import { Injectable } from '@nestjs/common';

@Injectable()
export class UsersService {
  private users = [];

  findAll() {
    return this.users;
  }

  create(user) {
    this.users.push(user);
    return user;
  }
}
```

## Providers in modules

Register services in the `providers` array of a module; also `export` them if other modules need them.