1. Major improvements to security.
Microsoft edge will now feature native bio-metric features so you wont have to worry about saving passwords.
Along with some improvements to the way windows defender works they are also adding a new product for enterprise users to detect attacks early.

2. Windows Ink.
"Quickly and easily take a note, sketch on a screenshot, or draw an idea.

Smart Sticky Notes help you remember common tasks like reminding you of flight times or offering directions using Maps.

Key apps have new ink-specific features, like using handwriting in Office, ink annotations in Microsoft Edge or drawing custom routes in Maps."

3. Improvements to Cortana
"Cortana is now available above your lock screen so you can do things like ask questions, play music from your PC or set a reminder without unlocking your device.

Cortana can save and recall key information, like your frequent flier number or where you parked at the airport. You can also add photos to make your reminders visual, like a photo of a bottle of wine you enjoyed at a restaurant.

Cortana can give you notifications across all the devices you have with Cortana – like sharing directions across devices or from text or messaging services on your phone."

4. Improvements to Microsoft Edge
"Building on strong power efficiency already available in Microsoft Edge, the Anniversary Update includes even more power-saving improvements, using fewer CPU cycles, consuming less memory, and minimizing the impact of background activity and peripheral content. Microsoft Edge lasts three hours longer than Google Chrome—long enough to finish the final movie in your favorite trilogy.

Microsoft Edge Extensions, such as Pinterest’s “Pin It Button,” Amazon Assistant, AdBlock, Adblock Plus and LastPass, will be available in the Windows Store with the Anniversary Update to add features to your browser and personalize your experience.

A new accessibility architecture for Microsoft Edge supports modern web standards, including HTML5, CSS3, and ARIA. With the Anniversary Update, page structure and content are now exposed more clearly with assistive technology. Visual presentation of web pages in high contrast mode is greatly improved to provide additional visual context, while preserving text contrast. Also, form entry when using keyboard navigation and screen readers improve in this update making the browsing experience for people of all abilities better."

Source: https://blogs.windows.com/windowsexperience/2016/06/29/windows-10-anniversary-update-available-august-2/