“Encryption” in modern data security generally refers to key-based cryptography. In short, you input the data you want to encrypt and the key (a string of letters, numbers, and/or symbols) you want to use to encrypt it. The combination of these two things creates a jumbled mess that can only be decrypted if the appropriate key is used.
The short answer is yes: encryption can be cracked. A brute force approach, which basically involves making lots and lots of guesses until one turns out to be right, would certainly find the right answer, given enough time and computing power. Encryption converts data into ciphertext, preventing hackers from accessing it in most cases. Though they certainly can try to bypass it, it could take several years, if you’re using 256-bit AES encryption. Luckily, most software uses this level of encryption. Unless you’re a person of extreme interest, it’s unlikely any hacker is going to spend time even trying.
But that doesn’t make encryption foolproof. Attackers are well aware that encrypted data is useless without keys, so what do they go after? The keys. The most catastrophic possible data breach is one in which the encrypted data and the decryption keys are stolen. If data security is being implemented correctly, the keys (multiple keys for different data, probably per user) will be securely stored in a separate location from the data and should probably be encrypted themselves. Additionally, the keys will need to be securely decrypted and fetched every time some data needs to be decrypted, so that attackers can’t intercept it. On top of all that, the keys should probably be changed on a regular basis.