Please exmplain n-tier

Question

I have inherited an n-tier application and I would like some explanation of its way of grouping files.

I guess BAL is the BUSINESS ACCESS LAYER
DAL is the DATA ACCESS LAYER

Any guesses for EAL? Anyone have any idea what EAL is?

Also, why would the file name content in the BAL be the same as the DAL?

http://i67.photobucket.com/albums/h292/Athono/01_zpsdeba4804.png

Selva Ganapathy · Answer

Hi Willian Thompson The EAL actually means Entity Framework Access Layer. And the EAL mainly used to access the Database of the ADO.net. Also used to connect the database. And the EAL is enables the developer to access the data as domain specific object and properties. For Eg EntityType ::= ENTITYTYPE nameOfEntity[BASE nameOfEntity [ABSTRACT true|false] KEY nameOfProperty[ nameOfProperty]* {(nameOfProperty PropertyType [PropertyFacet]*) +} PropertyType ::= ((PrimitiveType [PrimitiveTypeFacets]*) | (NameOfType) | RowType PropertyFacet ::= ( [NULLABLE true | false] | [DEFAULT defaultVal] | [MULTIPLICITY [ 1|*] ] ) PropertyTypeFacet ::= MAXLENGTH | PRECISION | SCALE | UNICODE | FIXEDLENGTH | COLLATION | DATETIMEKIND | PRESERVESECONDS PrimitiveType ::= BINARY | STRING | BOOLEAN | SINGLE | DOUBLE | DECIMAL | GUID | BYTE | SBYTE | INT16 | INT32 | INT64 | DATETIME | DATETIMEOFFSET | TIME ) Regards Selva Ganapathy K