Could you step me through some js code to get a few recent global tweets? Please show me how to authenticate as well.
Sure, I can guide you through the process of using the Twitter API to fetch a few recent global tweets using JavaScript. Here are the high-level steps we'll be following:

1. Create a Twitter Developer account and create a new app to get API keys and access tokens.

2. Install the twitter package using NPM.

3. Use the API keys and access tokens to authenticate with the Twitter API.

4. Use the twitter package to make a request to the Twitter API to get recent global tweets.

5. Parse the response to extract the necessary information.

Let's get started!

Step 1: Create a Twitter Developer Account
The first step is to create a Twitter Developer account and create a new app to get API keys and access tokens. Follow these steps:

1. Go to the Twitter Developer Platform website and sign in with your Twitter account.

2. Click on the Projects & Apps dropdown menu and select Overview.

3. Click on the Create App button.

4. Fill out the form with your app details (name, description, website, etc.) and click Create.

5. Click on the Keys and Tokens tab to get your API keys and access tokens.

Step 2: Install the twitter Package
Next, we need to install the twitter package using NPM. Run the following command in your terminal:

npm install twitter

Step 3: Authenticate with the Twitter API
To authenticate with the Twitter API, we'll need to use our API keys and access tokens. Create a new JavaScript file and add the following code, replacing the placeholders with your actual keys and tokens:

>>> javascript
const Twitter = require('twitter');

const client = new Twitter({
  consumer_key: 'YOUR_CONSUMER_KEY',
  consumer_secret: 'YOUR_CONSUMER_SECRET',
  access_token_key: 'YOUR_ACCESS_TOKEN_KEY',
  access_token_secret: 'YOUR_ACCESS_TOKEN_SECRET'
});

Step 4: Get Recent Global Tweets
Now that we're authenticated, we can use the twitter package to make a request to the Twitter API to get recent global tweets. Add the following code to your JavaScript file:

>>> javascript
client.get('search/tweets', {q: 'filter:safe', result_type: 'mixed', count: 10}, function(error, tweets, response) {
  if (error) throw error;
  console.log(tweets);
});

In this code, we're using the `get` method of the `client` object to make a request to the `search/tweets` endpoint of the Twitter API. The `q` parameter is set to filter:safe, which filters out tweets that may contain sensitive content. The `result_type` parameter is set to `mixed`, which returns a mix of popular and recent tweets. The `count` parameter is set to `10`, which means we'll get 10 tweets back.

Step 5: Parse the Response
The response from the Twitter API will be a JSON object containing information about the tweets. You can parse the response to extract the necessary information. Here's an example of how to extract the tweet text and user screen name:

>>> javascript
client.get('search/tweets', {q: 'filter:safe', result_type: 'mixed', count: 10}, function(error, tweets, response) {
  if (error) throw error;
  tweets.statuses.forEach(function(tweet) {
    console.log('Tweet Text: ' + tweet.text);
    console.log('User Screen Name: ' + tweet.user.screen_name);
    console.log('---');
  });
});

This code uses a `forEach` loop
I don't know much about NPM, does installing the Twitter package with NPM mean this only works in Node.js on the local machine? Or can you also install NPM packages for javascript programs that run in the browser and have this work on a webpage?
This code should also work in the browser, you can install npm modules in client side code.

npm is the package manager of the Node.js project, npm stands for Node Packaged Modules. It's a common misconception that since npm has Node in the name and is part of Node.js, it's only for serverside code. In fact, npm handles any Javascript you can think of, as long as it's in a node style module. This includes clientside code in the browser. 

Node style modules are incredibly simple and very general, a node module is just a compressed folder in .tar.gz format (similar to a .zip file) that contains at least a package.json file, and optionally any other files - such as source files - that you want to distribute. Because the module definition is so generic, npm is also able to distribute browser based libraries.

To use an npm library in the browser, you'll likely need to use a bundler tool like webpack or browserify that will automatically bundle all of your javascript dependencies into a single .js file you can serve with your website. After installing Twitter from npm, bundle it with webpack:
1) add import _ from twitter to your index.js file
2) run npx webpack to generate the bundle file with your npm module dependencies included.