user93585: Please take a look at this transaction link of bitcoin :
https://www.blockchain.com/btc/tx/blablablabla
My bitcoin address is :  blablablabla
You can see all of my transactions by this link :
https://www.blockchain.com/btc/address/blablablabla
My friend address is :  bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz
But you can't see all of his transactions by this link :
https://www.blockchain.com/btc/address/bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz

What is this address : bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz
And why is it undetectable?
How can i hide my transactions from others like that address?   

user26891: Bitcoin is not yet built with a privacy layer, all transactions are public and immutable, meaning they are visible to everyone, everywhere, forever.
If you wish to make a private transaction, you are better off using another blockchain like Monero, Zcash, or one of the many others focused on maintaining user privacy.

user38618: Your address is a classical 1 (Pay-to-public-key-hash) address. Your friend has a newer Bech32 Pay-to-Witness-public-key-hash-type address. The block explorer you referenced is partially compatible with Bech32. Sometimes, it doesn't work. On the other hand, there's nothing that prevents you from looking at your friend's transactions using a different block explorer such as https://Blockstream.info or https://blockchair.com/.

93585: <p>Please take a look at this transaction link of bitcoin :<br>
<a href="https://www.blockchain.com/btc/tx/blablablabla" rel="nofollow noreferrer">https://www.blockchain.com/btc/tx/blablablabla</a></p>

<p>My bitcoin address is :  <code>blablablabla</code><br>
You can see all of my transactions by this link :<br>
<a href="https://www.blockchain.com/btc/address/blablablabla" rel="nofollow noreferrer">https://www.blockchain.com/btc/address/blablablabla</a></p>

<p>My friend address is :  <code>bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz</code><br>
But you can't see all of his transactions by this link :<br>
<a href="https://www.blockchain.com/btc/address/bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz" rel="nofollow noreferrer">https://www.blockchain.com/btc/address/bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz</a>
<hr>
What is this address : <code>bc1qhkshfzwzm6cl8ezsg5fw7yhpsdqtp4r3vfzzzz</code><br>
And why is it undetectable?<br>
How can i hide my transactions from others like that address?   </p>
 26891: <p>Bitcoin is not yet built with a privacy layer, all transactions are public and immutable, meaning they are visible to everyone, everywhere, forever.</p>

<p>If you wish to make a private transaction, you are better off using another blockchain like <a href="https://www.getmonero.org/" rel="nofollow noreferrer">Monero</a>, <a href="https://z.cash/" rel="nofollow noreferrer">Zcash</a>, or one of the many others focused on maintaining user privacy.</p>
 38618: <p>Your address is a classical <code>1</code> (Pay-to-public-key-hash) address. Your friend has a newer <a href="https://bitcoin.stackexchange.com/questions/74791/what-the-difference-between-old-segwit-3-and-new-segwit-address-bc/74792#74792">Bech32</a> Pay-to-Witness-public-key-hash-type address. The block explorer you referenced is partially compatible with Bech32. Sometimes, it doesn't work. On the other hand, there's nothing that prevents you from looking at your friend's transactions using a different block explorer such as <a href="https://Blockstream.info" rel="noreferrer">https://Blockstream.info</a> or <a href="https://blockchair.com/" rel="noreferrer">https://blockchair.com/</a>.</p>
