Accent Sensitive and Accent Insensitive Collation in SQL Server explained

Accent insensitive collation considers the accented and unaccented versions of letters to be identical for sorting purposes.

Here is an example to test Accent sensitive (AS) and Accent insensitive (AI) collation difference.

We will compare values 'a' and 'á' in an Accent insensitive collation:

IF 'a' = 'á' COLLATE Latin1_General_CI_AI
SELECT 'Values are the same'
ELSE
SELECT 'Values are different'

Here is the result:

...which means that comparing 'a' to 'á' in an Accent insensitive collation treats the accented and unaccented versions of letters to be identical.

Then we will compare values 'a' and 'á' in an Accent sensitive collation:

IF 'a' = 'á' COLLATE Latin1_General_CI_AS
SELECT 'Values are the same'
ELSE
SELECT 'Values are different'

Here is the result:

...which means that comparing 'a' to 'á' in an Accent sensitive collation treats the accented and unaccented versions of letters differently.

See also:
Case Sensitive and Case Insensitive Collation in SQL Server explained
Width Sensitive and Width Insensitive Collation in SQL Server explained