Unity (user interface)
WordNet
noun
(1) The quality of being united into one
(2) The smallest whole number or a numeral representing this number
"He has the one but will need a two and three to go with it"
"They had lunch at one"
(3) An undivided or unbroken completeness or totality with nothing wanting
"The integrity of the nervous system is required for normal development"
"He took measures to insure the territorial unity of Croatia"