Should you bring a camera at all?

Technical Considerations:

• Size/Weight: There's no point to investing in a professional model that doesn't fit in your travel bag. Make sure that your choice isn't so hefty that you don't end up taking it out with you.
• Image Quality: This is the first thing that comes to mind, and probably the primary factor for your wanting to take along a camera on your travels. Anyone can Google a dark, blurry picture of the Eiffel Tower, but you want a crystal-clear portrait mode shot of yourself in front it.
• Zoom Range: Despite massive advances in smartphone camera technology, this is still one area in which your smartphones will tend to fall short compared to more powerful cameras equipped with zoom lenses. Make sure your pick has a decent optical zoom – the digital zoom capability is something you can edit with later.
• Compatibility: Do you want to check out your pictures at the end of every day instead of waiting for the end of the trip to get them developed? Then you'll want a digital camera, and even then, you may need a compatible device to view them on, as well as a connecting cable.
• Shooting Modes: Versatility is one of the other perks of toting around a camera — from drones that will give you aerial shots to camcorders for video quality, different devices offer different advantages over your standard phone cam.
• Price: Above all, don't purchase anything above your means. Budgeting for travel includes budgeting for the things you'll buy prepping for that travel — look at your funds and decide how much of that you want to allocate towards a new camera.

Specs:

• Type: This category typically either influences or determines everything else, but the individual models within a camera type vary. Still, there are generalities: mirrorless cameras will give you higher image quality at a heavier weight and higher price point, while compact cameras are your hanging-by-the-wriststrap casual cameras with lower quality but more convenient design. DSLRs were the authorities before mirrorless came along, and still boast a longer battery life, but have a slightly slower reaction speed. Camera phones are an obvious one, and film cameras are more niche and vary drastically in price and design. Drones are the newest thing, and popular for certain purposes. If you're going somewhere you need to keep an eye on your things or that isn't convenient to take fragile stuff to, then maybe avoid the chunky, expensive DSLRs. But if it's a shooting expedition, you might want to risk bringing a mirrorless model for the drastic increase in image quality.
• Continuous Shooting Speed: Measured in fps — that is, frames per second — this number is what you look at if you need your camera to be capable of quick shots for action scenes.
• Image File Format: An underrated feature, it can be important if you're travelling for a long time and want to be able to access your pictures externally from your camera ASAP. Make sure you can open and, if necessary, edit photos on your laptop or even phone (an adapter or external card reader may be needed as well).
• Max Video Resolution: This one is mostly for those people who want to edit a highlight reel of their travels, or vlog their trip. Otherwise, typical 1080p will do just fine for most purposes — you don't need to splurge on 4k unless you want to crop footage while retaining the quality (and you really don't need 8k unless you're a filmmaker).
• Megapixels: The unit itself (MP) denotes one million ("mega-") pixels, which essentially describes the detail of your photos. You can have too many megapixels, depending on your purpose — Instagram, for example, automatically downsizes overlarge images to 1.2MP.
• Sensor: Another determinant of image quality, sensor size and make is the main thing professional photographers look at. Bigger sensors have more pixels, which means better low-light and dynamic performance as well as reduced noise. However, smaller sensors have a better zoom range, and are both lighter and cheaper. DSLR and mirrorless cameras usually have full-frame (~36mm wide) or APS-C (22.3-23.6mm wide) sensors, while compact cameras have 1-inch (13.2mm wide) sensors. The iPhone 11 has a 1/2.55" sensor, for comparison, and that will give you 12MP images. For a more detailed guide to sensor sizes, check out this graphic.
  Credit: Hotshot997, Moxfyre
• Lens: Pro photographers will rattle off details about the makers and materials of camera lenses, but what you really need to know is mostly just aperture and focal length. So while names like the "Nikon AF-S 24-70mm f/2.8 E ED VR" look intimidating, they really just boil down to naming conventions that list brand, lens type/size (as covered above), focal length, maximum aperture, and miscellaneous details ("VR" here stands for vibration reduction) in that order. Focal length denotes zoom, and aperture is how much light the lens lets in, which affects exposure and depth of field. Zoom is fairly straightforward — some lens have ranges, while others have a fixed focal length, so you'll have to move to get your subject in frame. Aperture, on the other hand, is measured in fractions. A smaller aperture, say of f/11, gives you less background blur (like, the opposite of portrait mode), aka more depth of field, and a darker image. Larger apertures — f/2.8 is pretty standard — will give you a very focused effect with lots of light.