For both sounds, we put our tongue between our teeth and push air out between them.

The difference is, that the first one is voiced, which means we use our vocal cords.

And the second one is unvoiced, which means we don't use our vocal cords.

Okay, try this:

Voiced - vibrations.

Unvoiced - no vibrations.

Can you feel the difference?

Now let's practice with some common words you already know:

'This', 'thing', 'though', 'through', 'mother', 'birthday', 'clothes', 'fourth', 'bathe', 'bath'.

And of course, it helps to put them in a sentence.

'I never sunbathe, but I love a bath.'

But remember to say them out loud so you're practicing the pronunciation.