I have an old monitor that only has a VGA port.
I have a new Dell laptop that only has an HDMI port.
I want to use that old monitor with my new laptop.
Do I need a HDMI-to-VGA adapter or VGA-to-HDMI adapter? My common sense would tell a VGA-to-HDMI adapter, but I am not 100% sure.
I have seen some people in online forums talking about active and passive connectors. It is turning me crazy. I can't really grasp that. In layman's terms, what should I be using?
You need a HDMI-to-VGA adapter. Your laptop is outputting an HDMI signal which has to be converted to VGA.
Some connectors are physically different, but use identical signaling - in these cases a passive adapter is sufficient. Passive means there's no signal transformation necessary. It's just two different connectors wired together. For example, DVI-A is just repackaged VGA (aka D-Sub) and they can be passively adapted both ways. Similarly HDMI uses the same signaling as DVI-D, so you can convert between them without any electronics - just wires.
HDMI and VGA are completely incompatible, so you need an active adapter which will decode the HDMI signal and produce equivalent VGA signal.
You may be tempted to use a passive HDMI→DVI adapter and then a passive DVI→VGA adapter, but this won't work. HDMI would be converted into DVI-D, and the second adapter needs DVI-A input. DVI-D and DVI-A use physically compatible connectors, but the signal won't go through.
Note that while active adapters are directional (HDMI→VGA is completely different than VGA→HDMI), passive adapters are usually not. As long as passive adapter's plugs physically fit, it will work in both directions. So for example a HDMI→DVI adapter would work for DVI→HDMI too.
Many people get this the wrong way round.
Signals go from > to
You might think you're connecting your display to your computer, but you're not. You're connecting the computer to the display.
This means your signal goes from the computer to the display - that's an HDMI to VGA connection.
HDMI is a digital format, VGA is an analog format, so any connector you get must be an active connector.
I'll go through your Q point by point.
Do I need (hdmi to vga adapter) OR (vga to hdmi adapter)? My common sense would tell (vga to hdmi adapter), but I am not 100% sure.
Well, the exact naming of the adapter will depend on the vendor, but most vendors put the video source (computer) before the "to", and the video target (monitor) behind it. So "HDMI to VGA" would be an adapter for connecting an HDMI output to an VGA input, which is what you need. But the naming convention is not universal.
Note that HDMI-VGA adapters usually only work in one direction - so check the description for the adapter before buying, so you get the right adapter.
I have seen some people in online forums talking about active and passive connector. It is turning me crazy. I can't really grasp that. Can you tell me like a layman, what should I be using?
A "passive connector" is a connector that does not "do" anything - which means it does not have electronics inside that convert the signal. Instead it only electrically connects different plugs. That only works if the required signal itself is the same on both sides (or compatible). So passive connectors only work in certain situations. For example, you can go from DisplayPort to HDMI with a passive adapter (because DisplayPort was designed that way).
HDMI and VGA use completely different signals, so you need an "active connector" (or "active adapter"), which contains electronics that will convert the signal.
Further reading: How to convert HDMI to VGA or VGA to HDMI . This article gives more explanation about the technology required.
Wikipedia also has a section on HDMI to VGA conversion: HDMI - Legacy compatibility
It doesn't matter what it's called. Just go by picture. You want one that will go into your laptop's HDMI socket at one end, and fit your monitor's VGA cable at the other. For example:
A "passive connector" is a connector that does not "do" anything - which means it does not have electronics inside that convert the signal. Instead it only electrically connects different plugs. That only works if the required signal itself is the same on both sides (or compatible). So passive connectors only work in certain situations. For example, you can go from DisplayPort to HDMI with a passive adapter (because DisplayPort was designed that way Hdmi
Do you already have a cable that will connect either of these devices? If you do, that will determine which adapter to get.
Honestly, I'm not sure what these other answers are on about - it depends on what you already have.
If you have an HDMI Cable
Say you have an HDMI cable you can connect to your laptop, but you can't plug that into your monitor. Then you need an HDMI to VGA adapter.
Hdmi to VGA
If you have a VGA Cable
If you already have a VGA cable with your old monitor, but you can't plug it into your laptop, then you need a VGA to HDMI adapter.
VGA to HDMI
If you intend to buy a new cable
Typically one will simply buy a cable that has both (in which case, it doesn't matter which type is described first. Its just a cable that connects VGA to HDMI (or HDMI to VGA if you prefer). Depends how they choose to list the item.
The typical solution
