You see the code below, how I did use the session variable; So the three questions are; 1- Where are they stored? (Server or Client side) 2- Are they unique for each web page visitor? 3- Can I remove it using ajax or simple js code when my job is done with it? or it will be removed automatically..?

        sbyte[][] arrImages = svc.getImagesForFields(new String[] { "CustomerName", "CustomerSurName" });

        Dictionary<string, byte[]> smartImageData = new Dictionary<string, byte[]>();
        int i = 0;
        foreach (sbyte[] bytes in arrImages)
        {
            smartImageData.Add(fieldNames[i], ConvertToByte(bytes));
            i++;
        }

        Session.Add("SmartImageData", smartImageData);