Once on the Download page at https://www.wireshark.org/, you will see options for the type of file you want, along with what release. You can choose from stable, old stable, and development. The following screenshot shows the choices for downloads under Stable Release:

In most cases, you will select an option under Stable Release, as this is the most recent version of Wireshark, which has most of the bugs resolved and functions at an optimal level. The following lists the available choices:

• Windows Installer (64-bit): This provides a standard download for a 64-bit Windows OS.
• Windows Installer (32-bit): This provides a standard download for a 32-bit Windows OS.

• Wireshark PortableApps (32-bit): This is an option that you can run from a flash drive for troubleshooting without having to install on a system. However, the app is limited for use only with Windows 2000, XP, or Vista.
• macOS 10.12 and later Intel 64-bit .dmg: This is an option for macOS users. To install, download, and unpack the Disk Image (DMG) and then run the install. In some cases, you may have to complete additional configuration options in Wireshark to resolve any errors.
• Source Code: This provides an archive of the source code, where you can study the various files. If you are serious about development, then you should obtain and update your code from Wireshark's Git repository. Git will automatically merge changes into your personal source, so you can keep your source updated. The following is a screenshot of the Source Code option on the Download page:

Below the stable release, you will find two other options:

• Old Stable: This includes the same options as the stable release, but are older versions, rather than the latest build. This might be used if your organization has a strict change management policy that doesn't allow any new software until you run vulnerability testing. In that case, you can select an Old Stable option. 
• Development Release: If you would like to test new features, then you can select one of the choices under the Development section.

It's worth taking the time to explore all the resources on https://www.wireshark.org/, to help you learn more about packet analysis and find the latest information on Wireshark.