if i install os x el capitan will i lose everything

Use third-party editing extensions to take your photo editing to the next level.Sort your albums and the photos in them by date, title, and more.Add or edit location data, and batch change titles, descriptions, and keywords.Access your library on all your devices with iCloud Photo Library.Photos automatically organizes your library and helps you edit like a pro with simple and powerful editing tools.New ways to organize and enhance your images in Photos. Create notes on your Mac and they’ll automatically sync to your iOS devices using iCloud.Add content to a note directly from other OS X apps using the Share menu.Easily search and browse the content from all your notes in the Attachments Browser.Save rich content like photos, videos, documents, PDFs, web links, and map locations.Format your notes with titles, paragraph headings, bullets, numbers, and checklists.

An improved full-screen view lets you switch between your inbox and your draft email messages.

Mail automatically suggests contacts and events from your messages to help you keep your Contacts and Calendar organized.

Swipe right to mark as read or unread, or swipe left to delete.

Use your trackpad to manage your inbox with a swipe, just like on iPhone.

Resize the Spotlight window and move it anywhere on the screen.

Use your own words to search for files on your Mac, like “Documents I edited yesterday.”.

Search for weather, stocks, sports, web video, and transit information right in Spotlight.

Create a new desktop space easily by dragging a window to the top of your screen.

View all your open windows in a single layer with no overlap, so you can instantly find that window you’re looking for.

Take control of your desktop with Mission Control. Focus on two apps at once – neatly arranged side by side - in full screen without distractions.Make the most of your screen with Split View. This version of El Capitan can also be installed on Mac computers that are not compatible with High Sierra. If you are running Snow Leopard or Lion and would like to upgrade to High Sierra, you need to install El Capitan first. This version of OS X El Capitan is for users running OS X Snow Leopard or OS X Lion who would like to upgrade to macOS High Sierra.

If i install os x el capitan will i lose everything