Collation in SQL SERVER
It is a set of rules that determine how data is sorted and compared in SQL Server.
Character data is sorted using rules that define the correct character sequence, with options for specifying case-sensitivity, accent marks, kana character types and character width.
If A and a, B and b, etc. are treated in the same way then it is case-insensitive. A computer treats A and a differently because it uses ASCII code to differentiate the input. The ASCII value of A is 65, while a is 97. The ASCII value of B is 66 and b is 98.
If a and á, o and ó are treated in the same way, then it is accent-insensitive. A computer treats a and á differently because it uses ASCII code for differentiating the input. The ASCII value of a is 97 and áis 225. The ASCII value of o is 111 and ó is 243.
When Japanese kana characters Hiragana and Katakana are treated differently, it is called Kana sensitive.
When a single-byte character (half-width) and the same character when represented as a double-byte character (full-width) are treated differently then it is width sensitive.