Google Assistant offers a way of interacting with Google using only your voice. It is activated using the "OK Google" command, or by long-pressing the home button.

Google Assistant is built into Pixel phones and many other recent devices, and can be installed on any device running Android 5.0 Lollipop or later.

With Google Assistant you can do all the same things as you previously did with Google voice search, and there are even some new commands - the Google Assistant can tell you jokes and host games, for example.

The main difference between Google Assistant and regular voice search is the built-in AI. The service is significantly more intelligent with the Assistant onboard.

However, the basic command "OK Google" will work with any Android phone.

What is OK Google? 

"OK Google" is the voice command used to activate Google Assistant on your Android devices.

It's accessible in various ways - long-pressing the Home button, tapping the mic icon in the search bar and, assuming it's configured as such, using the "Ok Google" command from any app, even when the screen is switched off.

To configure the latter you need to access your Google Assistant settings. This is possible either by launching the Assistant and asking for 'Google Assistant settings' then tapping the link, or going in via a related app such as Google Home.

Select your device, then enable 'Access with Voice Match'. This lets you access Google Assistant even if you're in another app or your screen is off.

If you have other Google devices, such as a Google Home, you may actually want to disable this setting as it can often be picked up on your phone when you're trying to talk to the speaker instead.

What can you ask OK Google?

You can ask Google pretty much anything you like. It can set alarms, make calls and texts, schedule meetings and more on your Android device. Here are some basic commands (we've rounded up some funny questions to ask Google Assistant too):

•    Open (eg. techadvisor.co.uk, BBC iPlayer app)
•    Take a picture/photo
•    Record a video
•    Set an alarm for…
•    Set a timer for…
•    Remind me to… (includes times and locations)
•    Make a note
•    Create a calendar event
•    What is my schedule for tomorrow?
•    Where's my package?
•    Find…
•    Call…
•    Text…
•    Send email to…
•    Post to…
•    Where is the nearest…?
•    Navigate to…
•    Directions to…
•    Where is…?
•    Show me my flight info
•    Where's my hotel?
•    What are some attractions around here?
•    How do you say [hello] in [Japanese]?
•    What is [100 pounts] in [dollars]?
•    What's the flight status of…?
•    Play some music (opens "I'm feeling lucky" radio station in Google Play Music)
•    Next Song / Pause Song
•    Play/watch/read… (content must be in Google Play library)
•    What's this song?
•    Do a barrel roll
•    Beam me up Scotty (audio response)
•    Make me a sandwich (audio response)
•    Up, up, down, down, left, right, left, right (audio response)
•    Who are you? (audio response)
•    When am I? (audio response)

For example, you might tell it to "Call Jonathan Robson", "Show me walking directions to get home", "Text Margo to say I'll be home at half past seven", "Remember to book flights tomorrow", "Schedule a meeting tomorrow with Matt", "Open Calendar app", "Listen to Diamonds by Rihanna" or whatever you like.You can also use OK Google in the kitchen as a kind of sous chef. For example, as above, you could ask it "What's Kohlrabi?" when faced with an unknown ingredient in a recipe.

Speaking is usually quicker than typing, and using OK Google you can say "how far is it to..." and get a quick answer with a route in Google Maps from your current destination. You can be specific about the type of directions by qualifying the question: "Give me driving directions to Amsterdam".

If you're not in a position to use voice search, you can also type in your request. 

Also see how to fix problems with the "OK Google" voice command on Android smartphones.

Read next: Best new phones coming in 2018

Follow Marie Black on Twitter.