Which are two important components in ADO.NET?
DataReader and DataSet are the two fundamental objects in ADO.NET.
Can you differentiate between Array list and Hash table?
Hashtable stores using and value pair while array only stores values.
Can we have multiple web.config files in a project ?
Yes you can.
Explain the difference between throw and throw ex ?
Below is a nice video from youtube which explains the difference between them practically.
Can you explain what does it means by dataset is a disconnected architecture and data reader is connected ?
Disconnected architecture means dataset can hold data even if SQL goes down , connected architecture means datareader will always need SQL server live or else data reader object will throw a error.
Below is a video which demonstrates this concept.