BleepingComputer.com: File Extensions - what are they?

I googled but still don't understand what they are and why I need to know this! I do know I was told I need to know & understand and am sure I do. Just dense I guess . Send me to a tutorial so I can learn pls.

Kay

Okay, i'll try and explain the basics.

Firstly, a file extension explains to a program how to open the file. Sometimes these extensions are hidden for users that would change them and confuse the computer.

Why are there different types of files?

A computer has to distinguish between the formats. It is also easier for a computer to have all the knowledge of a file format than to make the file carry the instructions for the computer to use. Since it is a file, it is also more likely to be transferred between computers and corrupted, which would destroy the whole file.

Some basic image file extensions are(and why they are different)--

jpg(also known as .jpeg). It's a common extension. It retains most quality, but not all of it. It is called a "lossy" file format because of this. Saving as this file type and then opening it again will reduce quality each time you do it. Most cameras use this format, and it is avantageous because it saves space, and the little quality lost doesn't matter to most people, and even so it is less noticable in color photos.

.png A lossless file type that supports full transparency. Personally, this is what i use. It keeps its quality, but you pay for it in filesize.


.gif - An older filetype that converts the image into like 256 colors or something like that. It does allow for animations though, and i'm guessing its between .png and .jpg in size. Not good quality for large images.

.psd - photoshop file format. Used by Adobe, and not openable in most other programs. This format allows for layers and anything else photoshop does.



Why do you need to know this?

I found your helpful BC forum trying to copy and paste photos. Other people seem to send them just fine. I ran into the fact that I can not copy/paste photos in yahoo unless they were attachments. My friend had trouble uploading my attachments as it took her 30 minutes to do so.

So I started researching what I was doing wrong. Got some great easy to understand answers on BC. Piriforms suggested I research file extensions to understand them. Said I might be trying to send photos in the bmp format.

Today I finally downloaded the Irfanview and the helpful instructions given to me to Reduce & Resize the pics. Haven't tried anything yet as it is sooooo time consuming for all this stuff. I also tried downloading Max Registry Cleaner until I found out I had to pay for it (I am just laid off). Now I have a new problem.

I pay Poppit on Pogo. It won't load any more. I unistalled Sun Java & installed the latest version. I ran the checks to see if it was installed, if plug add ons was OK ,
if pop up blockers were interferring and I cleared the cache. Still won't work and yes I did restart the computer too. Any suggestions??

okay, the reason why you can't copy and paste photos into the internet is because they can't link to your computer and show them through there. They have to be hosted on a server, which then you can give a link to (like

http://www.example.com/image

) Then they could click on that and be redirected to the server that has the picture. Instead of doing this though, you can also upload it as an attachment on yahoo mail. some sites will only accept certain file types.

So, in short, you can't copy and paste a photo into the internet, because it has to be somewhere that another computer can get to. They can't directly connect to your computer. Thus, you have to get it on a server that will always be around to give them(or anyone else who gets ahold of the URL) the picture.

To send pictures, you have to get a server that will hold(host) the pictures on for you. photobucket and imageshack.us are two sites that allow you to do that. If you want it private though, you've got to go through emails. anyone can access those files on photobucket or imageshack if they get the link.

Also, remember yahoo mail, and most other emails are also limited to 10MB of data per message. So, you can't send videos or anything like that.

They tell the computer what kind of file it's looking at. if it's a .bat it tells the computer to run command prompt, if it's .png, fireworks (if you have it) or whatever other program... .doc, word .txt, notepad .bmp, pic viewer or paint. .aup audacity... .iso.... nero? .cue (basic cd caller) no real program exists I don't think .faa poweriso file .zip, windows self extractor .rar winrar .dll, warning saying this will kill your computer (it probably won't) PM me if you need any more

Programmes and applications use the file extension (file type, if you will) to understand what the file is and what to do with it. With photos, there are many different extensions, each of which reflects the internal structure of the actual file.

The easiest method of sending pictures or graphics is to do so as an attachment to the E-mail; this method attaches the file (includinging type extension) to the E-mail and avoids having to upload it to a server and send a link to it. If you are using Yahoo E-mail, look for the (almost universal icon) of the paperclip, browse through your picture files to find the one (or more) you want to send, and complete the attachment process. Remember, though, there is a size limit to the E-mail you want to send, so do not send a ton of pictures (even .jpegs) in one E-mail.