Tree

Tree[{subtree1,subtree2,…}] represents a tree with a list of child subtrees subtreei.

Tree[<|key1->subtree1,key2->subtree2,…|>] specifies the children as an association with keys keyi.

Tree[data,subtrees] represents a tree containing data in its root, with children given by subtrees.

Please visit the official Wolfram Language Reference for more details and examples on core symbols.