Global: These are large scale conflicts involving multiple people on both sides. The war that occurs just before the play opens and the conflicts between Scotland and England and among various clans and factions in Scotland are global conflicts.
Interpersonal conflicts: are those between two individuals or perhaps small groups. There are several in Macbeth including Macbeth-Banquo, Macbeth-Duncan, and Macbeth-Macduff, all of which end with murder.
Internal Conflicts: are ones where a person is of two minds about something. Macbeth's indecision about killing Duncan, Lady Macbeth's guilt, Banquo's initial ambivalence about the witches, etc. are all internal conflicts, some of which are resolved and some of which are not.