A map is an unordered collection of key-value pairs, where each key is unique. Maps are used to store data in an associative manner. Here's a basic overview of maps in Dart:

• Creating a Map: Use {key1: value1, key2: value2} syntax.

• Accessing Values: Use map[key] to get the value associated with a key.

• Adding Key-Value Pairs: Simply assign a value to a new key, map[newKey] = newValue.

• Changing Values: Assign a new value to an existing key, map[key] = newValue.

• Removing Key-Value Pairs: Use remove(key) to delete a key-value pair.

• Iterating Over Entries: Use forEach((key, value) => ...) to loop through entries.

• Checking Existence: Use containsKey(key) and containsValue(value) to check for keys and values.

• Keys and Values: Use map.keys and map.values to get lists of all keys and values.

• Typed Maps: Use Map<KeyType, ValueType> to specify types.

• Updating Values: Use update(key, (value) => newValue) to modify values.

• Conditional Addition: Use putIfAbsent(key, () => value) to add only if the key doesn't exist.

• Merging Maps: Use addAll(otherMap) to combine maps.

• Creating from List: Use {for (var item in list) key: value} to create a map from a list.

• Clearing a Map: Use clear() to remove all entries.