The final fifty years have witnessed numerous monographs and 1000s of study articles at the thought, positive equipment and huge spectrum of functions of boundary price difficulties for usual differential equations. during this substantial box of study, the conjugate (Hermite) and definitely the right point of interest (Abei) sorts of difficulties have acquired the utmost recognition. this is often mostly on account that some of these difficulties are simple, within the feel that the equipment hired of their learn are simply extendable to different different types of prob­ lems. additionally, the conjugate and the proper point of interest varieties of boundary price difficulties ensue often in actual global difficulties. within the monograph Boundary price difficulties for larger Order Differential Equations released in 1986, we addressed the idea of conjugate boundary price difficulties. at the moment the consequences on correct point of interest difficulties have been scarce; although, within the final ten years wide study has been performed. In bankruptcy 1 of the mono­ graph we provide updated info of this newly built idea of correct point of interest boundary worth difficulties. until eventually 20 years in the past distinction Equations have been regarded as the dis­ cretizations of the differential equations. extra, it used to be tacitly taken with no consideration that the theories of distinction and differential equations are parallel. in spite of the fact that, impressive diversities and broad purposes mentioned within the final 20 years have made distinction equations one of many significant parts of research.