What does res.render do, and what does the html file look like?

My end goal is to load arbitrary comma-separated-values from a text file into an html file (for example). I was only able to deduce that a view was the html file, and callback gives that html file back.

Here is the documentation: http://expressjs.com/api.html#res.render.

Now, given context from some example code I found, there is something about using ejs (embedded javascript) with <% and %>.

But if I may add, am I just incompetent or is the documentation really truly vague and assumes the reader knows everything? How could I have gone about figuring this out on my own? Is there any official documentation so I can gain a full understanding of usage, advantages and pitfalls?

Edit 1

I just want to add that I'm having a heck of a time learning node.js.
Is it me or is the general documentation really vague? Aside from lousy explanations like above, there are no type specifications for parameters or return values.

Edit 2

Let me ask you some more specific questions above the code.

The actual orders.ejs file is in views/orders.ejs. How does this code refer to it?

HTML excerpt:

<tbody>

  <% for(var i=0; i<orders.length; i++) {%>

     <tr>

       <td><%= orders[i].id %></td>

       <td><%= orders[i].amount %></td>

       <td><%= orders[i].time %></td>

     </tr>

     <% } %>

And the js. Please see /orders:

  // Define routes for simple SSJS web app. 

// Writes Coinbase orders to database.

var async   = require('async')

  , express = require('express')

  , fs      = require('fs')

  , http    = require('http')

  , https   = require('https')

  , db      = require('./models');



var app = express();

app.set('views', __dirname + '/views');

app.set('view engine', 'ejs');

app.set('port', process.env.PORT || 8080);



// Render homepage (note trailing slash): example.com/

app.get('/', function(request, response) {

  var data = fs.readFileSync('index.html').toString();

  response.send(data);

});



// Render example.com/orders

app.get('/orders', function(request, response) {

  global.db.Order.findAll().success(function(orders) {

    var orders_json = [];

    orders.forEach(function(order) {

      orders_json.push({id: order.coinbase_id, amount: order.amount, time: order.time});

    });

    // Uses views/orders.ejs

    response.render(orders, {orders: orders_json});

  }).error(function(err) {

    console.log(err);

    response.send(error retrieving orders);

  });

});



// Hit this URL while on example.com/orders to refresh

app.get('/refresh_orders', function(request, response) {

  https.get(https://coinbase.com/api/v1/orders?api_key= + process.env.COINBASE_API_KEY, function(res) {

    var body = '';

    res.on('data', function(chunk) {body += chunk;});

    res.on('end', function() {

      try {

        var orders_json = JSON.parse(body);

        if (orders_json.error) {

          response.send(orders_json.error);

          return;

        }

        // add each order asynchronously

        async.forEach(orders_json.orders, addOrder, function(err) {

          if (err) {

            console.log(err);

            response.send(error adding orders);

          } else {

            // orders added successfully

            response.redirect(/orders);

          }

        });

      } catch (error) {

        console.log(error);

        response.send(error parsing json);

      }

    });



    res.on('error', function(e) {

      console.log(e);

      response.send(error syncing orders);

    });

  });



});



// sync the database and start the server

db.sequelize.sync().complete(function(err) {

  if (err) {

    throw err;

  } else {

    http.createServer(app).listen(app.get('port'), function() {

      console.log(Listening on  + app.get('port'));

    });

  }

});



// add order to the database if it doesn't already exist

var addOrder = function(order_obj, callback) {

  var order = order_obj.order; // order json from coinbase

  if (order.status != completed) {

    // only add completed orders

    callback();

  } else {

    var Order = global.db.Order;

    // find if order has already been added to our database

    Order.find({where: {coinbase_id: order.id}}).success(function(order_instance) {

      if (order_instance) {

        // order already exists, do nothing

        callback();

      } else {

        // build instance and save

          var new_order_instance = Order.build({

          coinbase_id: order.id,

          amount: order.total_btc.cents / 100000000, // convert satoshis to BTC

          time: order.created_at

        });

          new_order_instance.save().success(function() {

          callback();

        }).error(function(err) {

          callback(err);

        });

      }

    });

  }

};