The first witch greets Macbeth as the thane of Glamis, which was his official title. The second witch, however, says
The third then says
These two predictions are a shock to Macbeth. He does not know that the current thane of Cawdor has been deemed a traitor and Duncan has ordered his title be given to Macbeth. When Banquo hears these predictions, he asks the witches to speak of his future as well, to which the third witch says
This prediction is what eventaully leads to Macbeth's plot to kill both Banquo and Banquo's son.
And to add to the above, of course there are the later predictions given to only Macbeth in Act 4, scene 1. They show him three apparitions and a vision. They promise him things as they did before, but this time the promises are not all as direct. They are riddles or half truths and not so easy to figure out by the literal minded Macbeth:
Macbeth! Macbeth! Macbeth! Beware
Beware the Thane of Fife. Dismiss me. Enough.
Be bloody, bold, and resolute; laugh to
The power of man, for none of woman born
Shall harm Macbeth.
Be lion-mettled, proud, and take no care
Who chafes, who frets, or where conspirers are:
Macbeth shall never vanquish’d be until
Great Birnam Wood to high Dunsinane Hill
Shall come against him.
The first prediction, told to him by a head in armor, is literally true: Macbeth should beware of Macduff (he will kill Macbeth in the end).
Second: a bloody baby tells Macbeth that he cannot be killed by anyone who was born of a woman. This is the riddle of the Caesarian child (Macduff). It's a trick meant to mislead Macbeth.
The third apparition is a young King with a branch in his hand who tells Macbeth he can't be defeated unless the forest that surrounds his castle comes up to the castle. This is another riddle, for the branches of the trees of the forest are used as camouflage, and the men are led on by the future king, Malcolm. Macbeth understands this one only when it's too late.
One final vision is "A show of eight Kings, and Banquo last with a glass in his hand." This suggests to Macbeth that generations of Banquo's offspring will all be kings.
Each of these visions, literally or figuratively as they may have been presented, will come true.
when they meet macbeth and banquo
for macbeth his already thane of Glamis and they sat he will be thane of Cawdor and then king and for banquo he will not be happy but happier lesser than macbeth but greater and his children will be king but not him
talk about the arnoured head
talks about the bloody child
and also finally the baby holding a tree
thats true but we can also take the three apparitions into consideration