What is SQL Server Browser? Browser Word Confuses me. Let see it in detail.

SQL Server Browser is the windows service which provides the information about the instance of SQL server running on the current computer.

SQL Server Browser provides the list of available server and helps to connect to the correct instance of SQL Server.

SQL Server Browser doesn’t enables on express edition by default. You need to configure it.

Developer Angle

Basically while connecting to the SQL Server on a machine which contains the other named instance of SQL server you need to provide the port number and IP to connect to particular server. If SQL Server browser service is running on your machine you can directly login i.e. SQL Server Browser Service will take care of it.