Explanation required line by line for API code in .NET CORE

[HttpPost]
//[ServiceFilter(typeof(CustomAuthenticationFilter))]
[Route(“get_all_products”)]
public async Task Get_All_Products([FromBody] Get_All_Products_Input ObjClass)
{
if (ObjClass == null)
{
return this.BadRequestCustom(ObjClass, null, _logger);
}
else
{
var result = await _settingsRepo.Get_All_Products(ObjClass);
if (result == null)
{
return this.NotFoundCustom(ObjClass, null, _logger);
}
else
{
List<Get_All_Products_Output> item = result.Cast<Get_All_Products_Output>().ToList();
if (item.Count > 0)
return this.OkCustom(ObjClass, result, _logger);
else
return this.Fail(ObjClass, result, _logger);
}
}
}