So what is the difference in Scottish-Irish history and Irish-Scottish history?

Scottish/Irish Irish/Scottish identification is of huge concern to many family historians.
So what is the difference in Scottish-Irish history and Irish-Scottish history?
According to wiki encyclopedia there is a “settled meaning today” of the different (so far I have counted 15) Irish/Scottish Scottish/Irish descendent patterns.
Where would a family historian look first to find Irish/Scottish roots?
Irish Scottish roots are a huge subject! It would be difficult to attack the subject as a whole. To help family historians, the ability to narrow your search can be very helpful.
When the immigrants from Ireland and Scotland came to America --- they came in waves based on many migration patterns.
If a researcher found a brick wall with more popular known events of migration, they limit their research of lesser known migration patterns.

START WITH GENEALOGY RESEARCH BASIC #1
-----start with what you know about your family

.
Birth place in Ireland or Scotland,
Dates migrated,
Departure and arrival ports will give you clues.
Occupations,
Examples: Coal miners in Pennsylvania/Pittsburgh
Laborers on the Erie Canal - 1820’s
Surnames, and
Neighbors on the census rolls are also great clues in deciding which of the many groups of Irish /Scottish your family may have descended.
Religion and religious affiliations are again strong indicators of your ancestors’ origin.
Catholic: Irish Catholics have been migrating to the United States in steady numbers even before the American Revolution, some as domestic servants or as a result of penal deportations.
Presbyterian: look in Ulster with families reaching to the 17th century
History is absolutely fascinating. The more I learn about my families past, the more I learn about history, lifestyles, politics, and the social climate of the time.

The terms Scots and Irish, while they have a settled meaning today*, are not always readily distinguished.

Sellar & Yeatman's spoof history 1066 and All That highlighted the confusion that these words can cause when used to refer to the past:
“ The Scots (originally Irish, but by now Scotch) were at this time inhabiting Ireland, having driven the Irish (Picts) out of Scotland; while the Picts (originally Scots) were now Irish (living in brackets) and vice versa. It is essential to keep these distinctions clearly in mind (and verce visa). ”

*while they have a settled meaning today
The patterns of Irish and Scottish migration have very set patterns.

I am devising an Irish Scottish table for research

The research table would allow a researcher to enter any of the above information and the logical first places to research would be the result.
It might be interesting to apply this theory with those interested in finding family and see if the table could bring results in individual cases.