Design an activity diagram for an online bookstore that allows users to browse books, search for specific titles, add books to a shopping cart, proceed to checkout, and make a purchase. The system should also handle user registration and login processes.

Steps to Create the Activity Diagram:

$1.$ Identify the Key Activities:

$-$User Registration

$-$User Login

$-$Browsing Books

$-$Searching for Books

$-$Adding Books to Shopping Cart

$-$Checkout Process

$-$Payment and Confirmation

$2.$ Define the Flow of Activities:

$-$Start with User Registration$/$Login$.$

$-$After login$,$ the user can either browse or search for books.

$-$From browsing or searching, books can be selected and added to the shopping cart.

$-$The user can then proceed to checkout.

$-$The checkout process includes payment and order confirmation.

$3.$ Incorporate Decision Points:

$-$After adding items to the cart, a decision point: continue shopping or proceed to checkout.

$-$During the checkout, a decision to confirm the order after payment details are entered.

$4.$ Include Parallel Activities if Any:

$-$While browsing, the user might be able to view book details and reviews simultaneously.

$5.$ Represent the End of the Process:

$-$The process ends with the confirmation of the order and a message displaying the expected delivery date.

$6.$ Use UML Notations:

$-$Use arrows for showing the flow of activities.

$-$Diamonds for decision points.

$-$Rectangular boxes for activities.

$-$Swimlanes if you need to differentiate roles $($e$.$g$.,$ user, system$).$