An Android emulator is software which simulates the functionality of an Android device running the Android OS
BlueStacks is a software platform which allows you to run Android apps on Windows and Mac, without the need of an Android emulator
"2 if your host machine laptop doesn t have more ram then you might want to find alternative android-emulator like genymotion bluestacks which takes less memory than android-emulator"
from question "Android emulator hangs forever at boot time"
"Yes some functionality possible only on device but you can try also bluestacks app player which has more possibilities than android-emulator"
from question "How to test iosched 2012?"
"This android-emulator works better than bluestacks"
from question "Running Instagram on AVD"
"In xda-forums i read about memu - most powerful android-emulator for pc better than bluestacks"
from question "Emulator error: This AVD's configuration is missing a kernel file"