Same notion of any. Put together under the same condition individual parts.
Eu trabalho todo dia.
I work everyday.
There are seven days in a week and I work on every single of them, no exception.
Eu gosto de todos os cachorros.
I like every dog.
There many dogs and I like every single dog, no exception.
Todo mundo gosta de chocolate.
Everyone likes chocolate.
There are billions of people and every single person likes chocolate.
Tip: as I highlighted for you, ‘todo’ always appears next to a noun, with which it agrees in gender (feminine, masculine) and number (singular, plural).
Opposite of nothing, it indicates totality. While ‘todo’ stresses the individual (each), ‘tudo’ focus on the idea of the whole.
Tudo que eu quero é sorvete.
All I want is ice cream.
Inside the world of things I want, ice cream is the only thing, constitutes the totality.
Eat your whole food, don’t leave anything on your plate.
Tip: it doesn’t vary. ‘tuda’ and ‘tudos’ do not exist.
Hope you learned a lot and come back for more.