Using i cloud photo library but keeping all my photos libraries on my MACS and IOS devices....

MY FULL PHOTOS LIBRARY OF 180 GB IS PARTIALLY ON MY MACBOOK PRO, FULLY ON MY IMAC AND MISC PARTS ON MY IOS DEVICES. IF I USE I CLOUD PHOTO LIBRARY (WITH THE 200 GB PLAN) WHAT SHOWS UP ON MY DEVICES? WILL IT BE THE COMPLETE PHOTOS LIBRARY AND NOT DUPLICATE SAME PHOTOS ON OTHER LIBRARIES OR WITHIN ANY OF THEM OR WILL IT INCLUDE ALL REPEAT PHOTOS FROM ALL LIBRARIES? ALSO WILL I STILL BE ABLE TO USE AND WORK WITH MY ORIGINAL PHOTOS LIBRARY THAT I KEEP ON A SEPARATE DRIVE AND PLUG INTO MY MACBOOK? just need help and advice it i should turn on iCloud photo library to view and organize my albums or just use the copy of photos i take with me on my portable drive and use that of view, share and work on... confused a little on what to do...