for long term purpose, which is better to invest in , Bitcoin or Ethereum ? Lets discuss that ..
For long term purpose, I think it will be better to invest in ethereum. Compared to bitcoin, ethereum is far cheaper (not to mention that ethereum is the second most expensive crptocurrency, next to bitcoin). And speaking of long term investment, it will be better to invest your money on ethereum (which value is rising) for you can buy more ethereums using your money compared to buying it with bitcoin (bitcoin value is about $4,300 today while ethereum has a value of around $300 today).
It doesn't matter if it is cheaper when the supply is much higher. It's basic economics.
Regarding the technology, they might face serious scaling problems in the future. So I can't see a good long term performance. Even if it continues to go up, it's very unlikely that it will outperform Bitcoin.