difference between ‘WITH NO CHECK’ and ‘NO CHECK’

Using WITH NO CHECK:

We have a table with 100 records.
1)Now we are creating a foreign Key Constraint by altering that table

ALTER TABLE [Sales].[SalesOrderDetailTemp]
    WITH NOCHECK
    ADD CONSTRAINT [FK_SalesOrderDetailTemp_SalesOrderHeader_SalesOrderID] FOREIGN KEY([SalesOrderID])
    REFERENCES [Sales].[SalesOrderHeader] ([SalesOrderID])

Here by using NOCHECK option
-->Foreign key does not Checks for old 100 records exists in References table (Salesorderheader)
-->Instead of Foreign key will check for New record inserted.

Using NOCHECK:

ALTER TABLE [Sales].[SalesOrderDetailTemp]
    NOCHECK CONSTRAINT [FK_SalesOrderDetailTemp_SalesOrderHeader_SalesOrderID]

This option Disables the Constraint of that Particular table