All DynamoDB tables and attributes need to have a UTF-8-encoded name, and there are some rules to how we can name them:

• Table and index names can have 3 to 255 characters which can include both upper case and lowercase letters, numbers, underscores, dashes, and dots.

• Attribute names can have 1 to 255 characters.
• When using expressions, there are certain reserved words that cannot be used as attribute names. Please refer to the Expression Attributes and Reserved Words links in the Further reading section of this chapter in case you need to use reserved words as attribute names.

Within attributes, the DynamoDB service supports the following data types:

• Scalar Types: A number, string, binary, Boolean, and null
• Document Types: A complex structure with nested attributes, such as a list or a map
• Set Types: Multiple scalar values represented as string set, number set, and binary set

Here are some examples of these data types that would be stored as an attribute written in JSON format and their representation in a DynamoDB table.