Gone are the days when watching a TV programme meant switching on your television set and tuning in to a particular channel at a particular time.
Now it's possible to view an episode of a TV show on your computer, tablet or smartphone. And you can also watch a movie or a short video over the internet too.
TV on demand
BBC iPlayer is an online service which allows you to play TV and radio programmes from the past week. It's often referred to as an 'on-demand' or 'catch-up' service. Many other channels offer a similar catch-up service to iPlayer. These services include ITV Player, 4oD Player (Channel 4) and Demand 5 (Five).
iPlayer is available on various internet-enabled devices. Take a look at the BBC Links section at the end of this guide for a comprehensive list of which devices and services offer iPlayer.
You can watch live BBC programmes on iPlayer, as well as a selection of programmes that have already aired during the past seven days. So, if you've missed a show or want to watch one again, you can check to see if it's available.
On-demand services, like iPlayer, allow you to play programmes (whether they are live or have already been broadcast) by 'streaming' them.
Streaming something means you can watch it without needing to store a large video file on your device - you simply view it using your internet connection. Streaming can be useful if you're on the move and want to catch live events or news using your laptop, smartphone or tablet.
When you are using an on-demand service, you may also be offered a video file to download to your computer or device. This means that you can watch the programme even when you don't have an internet connection.
Watching movies online
You can watch full-length films on a number of websites. Only a few films are featured on free catch-up TV services.
For a wider selection, you might want to sign up to a service you pay for. These provide an array of different shows, new films and even some original programmes which you can stream or download to your computer, tablet or smartphone.
You'll need to either pay a subscription fee (for streaming sites like Lovefilm and Netflix) or pay per film (for download sites such as Blinkbox and iTunes).
Some mobile services need a Wi-Fi connection to stream films and won't work if you're using your mobile network. Also, watching movies using your mobile network is likely to use up a lot of data. Keep an eye on your usage so you don't get landed with any surprise charges.
In order to play films you have downloaded to your computer, you may need to download additional 'plug-ins' (extra bits of computer software that let you view certain types of content).
See the Related Links section at the end of this guide for more information on how to watch films online.
Online video sites
There are a host of websites out there which allow you to view and share videos for free. Perhaps the best known one is YouTube. Other sites that are similar to YouTube include Vimeo and Dailymotion.
You can visit such sites just to watch other people's films, or you can create an account and upload your own videos for anyone to see ('upload' just means to post something - such as a video clip - onto the internet).
The video clips featured can be on just about any topic. To search the archive on each site, type what you are looking for into the search box. You can comment on and rate the clips. And you can see how many times a clip has been viewed.
Streaming video and downloading video content from the internet can really eat into any data allowance you may have as part of your broadband package. This is sometimes referred to as your 'data limit'.
Your data limit is the amount of digital information that you can download each month. It is measured in gigabytes per month or 'GB' for short. (You might also hear gigabytes referred to as 'Gig' or 'Gigs'.)
Find out what your data limit is by contacting your broadband provider. Otherwise you might find that if you repeatedly go over your limit, you are billed for extra costs or the price of your overall package increases.
Another thing you need to be aware of is how your broadband speed can affect any video services you want to watch.
Broadband speed is measured in megabits per second ('Mbps') or 'Mb' for short. (You might also hear megabits referred to as 'Meg' or 'Megs'.) The more data you download, the more megabits you will need.
If your broadband speed is slow - or if lots of people in your household are using the connection at the same time - the video you are streaming may keep pausing as you watch it. This is known as 'buffering'.
If you are unsure about your broadband speed and how this might affect what you watch online, the best thing to do is to contact your broadband provider. They will be able to tell you what your connection speed is and give you more information.