Create Table TestTable
(RegID int,
FirstName varchar(10),
Lastname varchar(10)
)

Insert Into TestTable Values (1, 'Larry', 'Cook')
Insert Into TestTable Values(2, 'John' , 'Adams')
Insert Into TestTable Values(3, 'Hariett','Conner')

Select *
From TestTable

Select *
Into TestTable_1
From TestTable

Insert Into TestTable Values(4, 'Paul','Sorbet')

Select *
From TestTable_1

Select Distinct t2.*
From TestTable t1
Inner Join 
TestTable_1 t2 ON t2.RegID = t1.RegID

Select Distinct t2.*
From TestTable t1
Left Join 
TestTable_1 t2 ON t2.RegID = t1.RegID

Select Distinct t2.*
From TestTable t1
Right Join 
TestTable_1 t2 ON t2.RegID = t1.RegID

Select Distinct t2.*
From TestTable t1
, 
TestTable_1 t2 
WHERE 
t2.RegID <> t1.RegID
OR t2.FirstName <> t1.FirstName
OR t2.LastName <> t1.LastName

Update TestTable_1
Set FirstName = 'Pete'
WHERE RegID = 4

Select t2.*
From TestTable t1
Join TestTable_1 t2 On t2.RegId = t1.RegId

WHERE 
t1.RegId <> t2.RegId
OR t1.FirstName <> t2.FirstName
OR t1.LastName <> t2.LastName