Bitlocker function

The short answer is that BitLocker requires a TPM 1.2 or newer chip on the motherboard and a Pro version of Windows or better; the Home versions don't have it.  Most systems made over the last several years have TPM chips -- including the Latitude 3350 according to<ADMIN NOTE: Broken link has been removed from this post by Dell>.  (Note: That page does NOT list some older models that nonetheless have TPMs, fyi, so don't assume that a certain model doesn't have a TPM just because it isn't listed there.)  However, there are cases where a system model typically has a TPM, but units of that model sold in certain countries don't include it because of regulatory requirements around TPMs in that country or something.

The reason I mentioned that was the "short answer" is that there are exceptions to both halves of that first sentence.  If you have a Pro or better version of Windows but do not have a TPM, then you can use Group Policy Editor to have BitLocker allow using a regular password to unlock the system.  BitLocker defaults to storing its decryption key in the TPM on the motherboard (and you can optionally add a PIN that you would be prompted to enter at boot), but it can be forced to allow using a regular password, which does not require a TPM.  The reason this isn't enabled by default is that it's less secure, mostly because a password doesn't allow BitLocker to perform "platform integrity checks" at boot that it can perform when a TPM is used.  Basically, using a TPM means that BitLocker can enter a sort of "lockdown" mode where it refuses to release the key if it detects a hardware or firmware change to your system that could potentially compromise system security and therefore the decryption key.  But if you're just prompted to enter a password at each boot, BitLocker can't perform that check, so you could potentially provide your password to your compromised system.

The other exception is that on some Windows 10 Home systems, a significantly scaled down version of BitLocker just called "Device encryption" is sometimes available.  Your system has to meet certain hardware requirements (including a TPM, and I don't remember the other requirements offhand), and you have to link your Windows logon account to your Microsoft account, and you can only encrypt your Windows partition.  You can't encrypt other partitions, flash drives, etc. like you can with full BitLocker, and you can't customize other settings like requiring a PIN at startup.

However, if you have Windows 10 Home and no TPM, then no version of BitLocker is available at all.  In that case, you may want to look into VeraCrypt, which is free, open source, and is based on TrueCrypt, which was actually audited by security professionals before support for it was dropped.  It doesn't require a TPM or a Pro version of Windows.

Thank you for your comprehensive response, I will therefore look for the laptop with this feature on the motherboard.