Let's look at the basic concepts of DynamoDB.
DynamoDB stores data in tables. A table contains multiple rows which are known as items. DynamoDB is not restricted to storing an amount of data in one table. While creating the DynamoDB table, we need to provide primary key attribute(s), which will identify the items uniquely:
Figure 6.1: Basic concepts
Items are similar to relational database table rows or tuples. We can store any amount of items in one table. A table can contain only unique (single or composite) primary keys of each item. If the new item contains the same primary keys that are already present in a table, it will override the item with the new one. In the preceding sample table, we can see that two items are created in the table. The maximum size of a single item can be up to 400 KB, which includes all the attributes (columns).