diff --git a/Sources/PNDependencyGraph/PNNode.swift b/Sources/PNDependencyGraph/PNNode.swift
index 321c31c..5e21e87 100644
--- a/Sources/PNDependencyGraph/PNNode.swift
+++ b/Sources/PNDependencyGraph/PNNode.swift
@@ -1,23 +1,64 @@
 import Foundation
 
+/// A node in a dependency graph.
+///
+/// The `PNNode` class represents a single node within a dependency graph. Each node
+/// has a unique identifier and can have dependencies on other nodes.
+///
+/// Example usage:
+/// ```swift
+/// let node = PNNode(identifier: "node1")
+/// let dependency = PNNode(identifier: "node2")
+/// node.addDependency(node: dependency)
+/// ```
 public final class PNNode: @unchecked Sendable, Equatable {
+    /// Compares two `PNNode` instances for equality.
+    ///
+    /// Two nodes are considered equal if they are the same instance (identity comparison).
+    ///
+    /// - Parameters:
+    ///   - lhs: The left-hand side node to compare.
+    ///   - rhs: The right-hand side node to compare.
+    /// - Returns: `true` if the nodes are identical; otherwise, `false`.
     public static func == (lhs: PNNode, rhs: PNNode) -> Bool {
         lhs === rhs
     }
 
+    /// A unique identifier for the node.
     public let identifier: String
+
+    /// The dependencies of this node.
+    ///
+    /// This property returns an array of nodes that this node depends on.
+    /// The dependencies are thread-safe and can be accessed from multiple threads.
     public var dependencies: [PNNode] {
         synchronization.withLock {
             unsafeDependencies
         }
     }
+
+    /// The internal storage for dependencies.
+    ///
+    /// This is used internally to store the actual dependencies in a thread-safe manner.
     private var unsafeDependencies: [PNNode] = []
+
+    /// A lock used to synchronize access to dependencies.
+    ///
+    /// This ensures that the `dependencies` property can be safely accessed from multiple threads.
     private let synchronization = NSLock()
 
+    /// Initializes a new instance of `PNNode` with the specified identifier.
+    ///
+    /// - Parameter newIdentifier: A unique identifier for the node.
     init(identifier newIdentifier: String) {
         identifier = newIdentifier
     }
 
+    /// Adds a dependency to this node.
+    ///
+    /// This method adds a node to the list of dependencies for this node.
+    ///
+    /// - Parameter node: The node that this node depends on.
     public func addDependency(node: PNNode) {
         synchronization.withLock {
             unsafeDependencies.append(node)
diff --git a/Sources/PNDependencyGraph/Visitors/PNMultithreadVisitor.swift b/Sources/PNDependencyGraph/Visitors/PNMultithreadVisitor.swift
index 0d0b909..8c74626 100644
--- a/Sources/PNDependencyGraph/Visitors/PNMultithreadVisitor.swift
+++ b/Sources/PNDependencyGraph/Visitors/PNMultithreadVisitor.swift
@@ -1,14 +1,37 @@
 import Foundation
 
+/// A multithreaded visitor for traversing a compiled dependency graph.
+///
+/// The `PNMultithreadVisitor` class allows for concurrent traversal of a dependency graph,
+/// executing node visits in parallel using an operation queue. It ensures that the first
+/// node is visited synchronously while all other nodes are processed in parallel.
+///
+/// Example usage:
+/// ```swift
+/// let visitor = PNMultithreadVisitor(graph: myGraph)
+/// visitor.visit { node in
+///     print("Visiting node: \(node)")
+/// }
+/// ```
 public final class PNMultithreadVisitor {
     private let graph: PNCompiledGraph
     private let queue = OperationQueue()
+
+    /// Initializes a new instance of `PNMultithreadVisitor` with the specified graph.
+    ///
+    /// - Parameter newGraph: The compiled dependency graph to visit.
     public init(graph newGraph: PNCompiledGraph) {
         graph = newGraph
         queue.qualityOfService = .userInitiated
         queue.maxConcurrentOperationCount = graph.nodes.count - 1
     }
 
+    /// Traverses the dependency graph, visiting each node.
+    ///
+    /// The first node in the graph is visited synchronously, while all other nodes
+    /// are processed concurrently in an operation queue.
+    ///
+    /// - Parameter completion: A closure to be called for each visited node.
     public func visit(completion: @Sendable @escaping (PNNode) -> Void) {
         guard let first = graph.nodes.first else {
             return
diff --git a/Sources/PNDependencyGraph/Visitors/PNSingleThreadVisitor.swift b/Sources/PNDependencyGraph/Visitors/PNSingleThreadVisitor.swift
index 62739c1..1864836 100644
--- a/Sources/PNDependencyGraph/Visitors/PNSingleThreadVisitor.swift
+++ b/Sources/PNDependencyGraph/Visitors/PNSingleThreadVisitor.swift
@@ -1,9 +1,31 @@
 public final class PNSingleThreadVisitor {
+    /// A single-threaded visitor for traversing a compiled dependency graph.
+    ///
+    /// The `PNSingleThreadVisitor` class allows for sequential traversal of a dependency graph,
+    /// executing node visits in a single thread. All nodes are processed in the order they appear
+    /// in the graph.
+    ///
+    /// Example usage:
+    /// ```swift
+    /// let visitor = PNSingleThreadVisitor(graph: myGraph)
+    /// visitor.visit { node in
+    ///     print("Visiting node: \(node)")
+    /// }
+    /// ```
     private let graph: PNCompiledGraph
+
+    /// Initializes a new instance of `PNSingleThreadVisitor` with the specified graph.
+    ///
+    /// - Parameter graph: The compiled dependency graph to visit.
     public init(graph: PNCompiledGraph) {
         self.graph = graph
     }
 
+    /// Traverses the dependency graph, visiting each node in sequence.
+    ///
+    /// All nodes in the graph are visited one after another in the order they appear.
+    ///
+    /// - Parameter completion: A closure to be called for each visited node.
     public func visit(completion: (PNNode) -> Void) {
         for node in graph.nodes {
             completion(node)