This is the 926th most frequent Portuguese word.
haver
"To exist," "to have" (auxiliary verb), or "there is/are."
"Haver" is used to question the existence or amount of something, coupled with "devem" to express estimation.
Quantos anos devem haver entre essas duas fotos?
How many years must there be between these two photos?
The word "há" is used impersonally, equivalent to "there is" in English, denoting the existence or occurrence of the meeting.
Há uma reunião agendada para amanhã.
There is a meeting scheduled for tomorrow.
"Haver" is used in the infinitive form to indicate existence or necessity, combined with "dever" to express necessity or a suggestion.