Berkeley's idealism is "representational", subjectivist, empiricist, epistemological, whereas Hegel's idealism is more like ontological realism. For Hegel subject is the constitution of reality itself. Subject and object are more or less identical. Perception is only a moment in a dynamic constitution or development of the absolute knowing (which is the presentation of the identity of subject and object). Hegel's point of view is not a general particular subject but holistic. Absolute knowing is concretely realized through spirit i.e. history, culture, art, religion, philosophy. Absolute means that there is something trans-historical, trans-subjectivist (infinite vs. finite).
The following is from the Stanford Encyclopedia of Philosophy:
"The pantheistic legacy inherited by Hegel meant that he had no problem in considering an objective outer world beyond any particular subjective mind. But this objective world itself had to be understood as conceptually informed: it was objectified spirit. Thus in contrast to Berkeleian subjective idealism it became common to talk of Hegel as incorporating the objective idealism of views, especially common among German historians, in which social life and thought were understood in terms of the conceptual or spiritual structures that informed them. But in contrast to both forms of idealism, Hegel, according to this reading, postulated a form of absolute idealism by including both subjective life and the objective cultural practices on which subjective life depended within the dynamics of the development of the self-consciousness and self-actualization of God, the Absolute Spirit."
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“Idealism” is a term that had been used sporadically by Leibniz and his followers to refer to a type of philosophy that was opposed to materialism. Thus, for example, Leibniz had contrasted Plato as an idealist with Epicurus as a materialist. The opposition to materialism here, together with the fact that in the English-speaking world the Irish philosopher and clergyman George Berkeley (1685–1753) is often taken as a prototypical idealist, has given rise to the assumption that idealism is necessarily an immaterialist doctrine. This assumption, however, is mistaken. With the possible exception of Leibniz, the idealism of the Germans was not committed to the type of doctrine found in Berkeley according to which immaterial minds, both infinite (God’s) and finite (those of humans), were the ultimately real entities, with apparently material things to be understood as reducible to states of such minds—that is, to ideas in the sense meant by the British empiricists.
As Leibniz’s use of Plato to exemplify idealism suggests, idealists in the German tradition tended to hold to the reality or objectivity of ideas in the Platonic sense, and for Plato, it would seem, such ideas were not conceived as in any mind at all—not even the mind of Plato’s god. The type of picture found in Berkeley was only to be found in certain late antique Platonists and, especially, early Christian Platonists like Saint Augustine, Bishop of Hippo. But especially for the German idealists like Hegel, Plato’s philosophy was understood through the lenses of more Aristotelian varieties of neo-Platonism, which pictured the thoughts of a divine mind as immanent in matter, and not as contained in some purely immaterial or spiritual mind. It thus had features closer to the more pantheistic picture of divine thought found in Spinoza, for example, for whom matter and mind were attributes of the one substance."
https://plato.stanford.edu/entries/hegel/#Aca