Instagram is a mobile app that you can download on iOS and Android phones and tablets as well as Windows Phone 8 and later versions. Keep in mind that you can only share photos and videos from the mobile app.
For details on setting up an account follow think link: https://help.instagram.com/1642053262784201/
Instagram is an online mobile photo-sharing, video-sharing, and social networking service that enables you to take photos and videos, and share them either publicly or privately on the app, as well as through Facebook, Twitter, Tumblr, and Flickr.
Instagram has a visual focus! Users want to scroll through fun and beautiful photos. There are lots of great filters to use on your photos within the app. You can take photos directly with the app or use your library photos and apply filters later, then post them.
Chances are many of your social media friends are already using Instagram.
Head to your profile tab and select “Find Friends.” You may search for friends who have connected their Facebook and Twitter accounts to Instagram, or you may input your phone’s contact list to find more friends. You can also search by name, username or tag (e.g. “#Hockey”).
Posting: Click the camera button in the center of your Instagram navigation panel to select library, photo or video to post. You then will have options to add a filter or border to your photo.
Each time you upload a photo to Instagram, you’ll have the option to share to each of the social networks you’ve enabled, or to none. If you choose to share to no social networks, the photo will post only to Instagram, viewable only by those users who follow you on the app.
Videos: With Instagram video, you can record short video clips ranging anywhere from three to fifteen seconds long. To record video, press the camera button and choose the video recorder option on the right. You can choose an existing a video in your phone’s gallery. iPhone users can upload multiple saved videos, splicing them together.