You can display certain widgets on your front page, a different set of widgets on your About page or Contact page and a completely different set of widgets on your posts, or specific categories.
Adding category specific widgets in WordPress
Step 1: Log in to your Dashboard, hover over JetPack and go to Settings.
Step 2: Scroll down till you see Widget Visibility. Click on the module name and click on Activate.
Step 3: If you want to create an image for your category.First upload the image to your media gallery.
Step 4: Go to Appearance > Widgets and drag the Image widget to your sidebar.
Step 5: Fill out the fields for image URL, and the image size to make sure it displays correctly.
Step 6: Click on the button that says Visibility and select Show. Change the desired widget type from the drop down menus. Then click Save.
Now the widget will show up only in posts that belong to the specified category.