Acronis discription of Incremental vs Differential backup???

Computer Type: PC/Desktop
System Manufacturer/Model Number: Custom built
OS: Win-7 32bit. 64bit, Win-10 and XP
CPU: i5-3570K 3.40Ghz
Motherboard: GA-Z77-HD3
Memory: 16 GB
Graphics Card: NVIDIA GeForce 1050
Sound Card: On Motherboard
Monitor(s) Displays: Asus VP278H-P
Screen Resolution: 1920x1080
Keyboard: Fujitsu FKB70D (dont laugh)
PSU: EVGA 550W
Case: Gigabyte
Hard Drives: Samsung 840 EVO 120GB SSD Samsung 840 EVO 250GB SSD Samsung 850 PRO 256GB SSD WDC_WD1001FALS-00E8B0
Internet Speed: 15
Browser: Mostly Fire Fox
Antivirus: Windows Defender

Computer Type: PC/Desktop
System Manufacturer/Model Number: Two HP Desktops. One in the Laundry Room / Bed Room.
OS: Microsoft Windows 7 Professional 64-bit 7601 Multiprocessor Free Service Pack 1
CPU: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
Motherboard: Hewlett-Packard 3396
Memory: 8.00 GB
Graphics Card: Intel(R) HD Graphics 4000
Sound Card: (1) Realtek High Definition Audio (2) Intel(R) Display Aud
Monitor(s) Displays: Hanns-G
Screen Resolution: 1440 x 900 x 32 bits (4294967296 colors) @ 59 Hz
Keyboard: Logitech K740.
Mouse: Microsoft Optical Mouse 1000.
PSU: Whatever came with the CMT.
Case: HP CMT Black.
Cooling: Whatever came with the CMT.
Hard Drives: (1) ATA WDC WD40EZRX-00S SCSI Disk Device (2) HP Officejet Pro 86 USB Device (3) WD My Book 1230 USB Device
Internet Speed: Spectrum 25Mbs.
Browser: EDGE
Antivirus: WebRoot, Microsoft Security Essentials.
Other Info: HP Officejet Pro 8600 Plus. WD MyBook 4TB.