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An array is a block of contiguous memory of fixed size that holds one or more objects of a given type.
A heap is a binary tree in which each element has a key (or sometimes priority) that is less than (or greater than) the keys of its children. This property is called the heap property or heap invariant. Heaps can be used to implement priority queues.
A linked list is a data structure where elements (often called nodes) are connected in a sequence, with each node containing both data and a reference (or "pointer") to the next node in the sequence.
Intervals, or array intervals, refer to a contiguous sequence of elements from an array, starting at one index and ending at another ([start, end]).
A string is a data type in programming that represents a sequence of characters.
A tree is a hierarchical data structure that consists of nodes connected by edges. Each node in a tree can be connected to one or more child nodes (depending on the type of tree) or no nodes if it is a leaf node. Each node can be connected to exactly one parent—except for the root node, which has no parent.