What is a Internet Cookie?

If you logged into this site, you probably have a Wordpress authentication cookie in your web browser.  Unless you recently cleared it, your browser probably has dozens or even hundreds of these small pieces of code.  But what are they, and what are they used for?

Internet cookies are small pieces of code that are downloaded to your internet browser.  Usually, you get them from websites that you visit.  These cookies have many different functions.  Some of these functions improve the user experience, while others are potential problems.  For example, a very common type of cookie is an “authentication cookie”.  This is used to store login information.  Basically, this is one of several possible ways a website knows who is logged in.  While many modern websites do not use this method, in early commercial websites cookies were often used to keep track of what a user had in a shopping cart.

However, while most cookies are safe cookies may cause problems on your computer.  Cookies can be used to track things you do online.  They do not necessarily stop sending information when you finish using a site.  This can be a serious privacy issue.  For example, a website you visited months ago may still be receiving information from your computer.  This can be a risk to privacy and may open you up to security threats.

You may choose to block cookies from your browser settings.  Most internet browsers have an option that will allow you to block cookies.  Another option, and one I recommend, is to clear your cookies occasionally.  Many computer optimization software tools clear Internet cookies.

I hope this answers some questions and I hope you enjoyed reading this.

Please send me more questions in the comments section!

What is a Vector Graphic?

Two terms you will encounter frequently when you discuss creating images on a computer are “vector” and “bitmap”.  Both are types of image and both have distinct uses.  You have probably encounter both types many times without noticing.  The primary difference between the two types is how the information is stored.  This difference leads to several important distinctions in how the images appear and how they are used.

In a bitmap image, which is sometimes called a raster image, the picture is in the form of pixels.  Each pixel is in a specific location and is a very specific color.  For example, a digital photograph consists of thousands of tiny squares which create images.

For example, just look at this photograph of some purple flowers.  It consists of approximately, 800,000 pixels and when you zoom in on it tightly you can see them.

Just look at this very tight close up on one of the flowers.  You can see around the edges of the flower where the pixels are visible.

All bitmaps store information in the form of pixels.  This has the advantage of being able to support very detailed images, that have realistic color variation.  However, this can also be a disadvantage.  As you can see, when you zoom in tightly on a bitmap, the you see individual blocks of color.  This is why there is often a limit on how much you can enlarge a photograph before it begins to look odd.  This is also why measurements like “dpi” or “ppi” (which stand for “dots per inch” and “pixels per inch” respectively) are relevant.  The more pixels in one inch, the more you can enlarge the image before it starts to look strange.

Vectors graphics work on a completely different principle.  Rather than storing the image as individual pixels, it stores the image mathematically.   Vector images are understood in terms of points, curves and mathematical formulae.  This allows for the storage of extremely complicated shapes.  For this reason, vectors are very scalable.  To increase the size of the vector image, simply adjust it mathematically and the image will be unchanged.  Vectors are excellent at shapes and designs.  They are frequently used in logos and drawings.  However, they do not work well for subtle color variation or photo realism.  Vector images often look like drawings or have a “cartoony” look.

For example, here is a very roughly created image of a similar flower.  It consists of five round shapes, each with a few additional points to give them more “petal” like appearance.

Obviously, this is a very crude graphic, but it does a good job of illustrating some of the characteristics of vectors that might not be as obvious in a more complex drawing.  Each “petal” is defined by six nodes and each node two other points determining the curve of the line connecting it to the next node.  The center of the flower is simply an ellipse.  However, because the shapes are defined by curves, when you zoom in, there is no change in the image.  You can zoom in as tightly as you like or increase the size of the image and the curves do not change.

This is a zoomed in look at one of the petals.  Notice how it keeps its shape and color.

Both bitmaps and vectors have many uses.  I enjoy working with both.

I hope you liked reading this article and please post your questions in the comments!

Note: Most webpages, including this one, prefer to handle bitmaps rather than vectors.  All of the vector images in this post were converted into bitmaps for viewing.

What is Open Source Software?

If you have been reading my previous posts, you may have noticed that I often direct people to various pieces of software.  I have pointed readers to a number of downloads, and keep a list of recommended pieces of software.  All of the software I recommend is free.  Some of the downloads I suggest, like CCleaner or Malware Bytes have both paid and free versions.  However, most of the software I recommend is open source software.  Open source software is almost always free, but this is not a requirement.

So what is the difference between open source software and other software?  Open source software is unique because the code (which is often called the source code) is available for anyone to access or modify to suit their needs.  Most commercial software is proprietary, which is also called closed source, which means that it can only be modified by the team that created the original work.  Open source software allows anyone to access the code and modify it.  Open source projects are usually highly collaborative efforts with many coders.  Open source software does have licenses, just as most other software, that prohibits users from doing things like selling the code.  However, users can make their own additions and are encouraged to, or in some cases required to, share those changes with others.  This often creates excellent programs that can compete with their closed source counterparts.

Saving and Overwriting — Or What is Difference Between Save and Save As?

This post is dedicated to a very common mistake that can cause a great deal of frustration when made.  How many of my readers are familiar with this scenario, I know that I certainly am.  You open up a document in a word processor.  The document is very long and you decide that you want to make a shorter version to print out and save the long one for an electronic version.  You delete a lot of text, some figures and a few charts.  You think you are finished and so you go to save the document.  Here is where horrible mistakes are made.  You are distracted, you click “Save”, because that is what you do with documents, and go on about your day.  When you go to get the long version out to print, it is gone and in its place is the much shorter version that you just created.  You have just been a victim of an overwritten document. If you had clicked “Save As” you would have stored your shorter version under a new name and instead of losing your original you would have had two separate documents.  This is why the distinction between “Save” and “Save as” is so important.

When you save something, you are replacing whatever currently exists at that file location with what you are currently working on.  This is fine as long as you do not want to access the old version.  When you use “Save as” you are creating a new file location distinct from the original one.  This allows you to have more than one version of the same document.

When dealing with the scenario we discussed earlier, it is sometimes possible to retrieve overwritten documents.  Some software, such as Microsoft Word, allows you to access previous versions for just this purpose.  Also, you may use backups or various software to retrieve overwritten files.

I hope this is useful and thank you for reading!

Recycling Bin and Recovery — Or Why Simply Hitting “Delete” Isn’t Enough

This is another post in my discussion of managing stored files.  In this post, I will be talking a bit about deleting files and the difference between sending a file to the recycling bin and actually getting rid of it.  This is very basic, but extremely useful if you are like me and sometimes delete more than you want to.

You make like to follow along on your own computer here.  I am using a Windows computer, so some of instructions may be a bit different if you are using another type of operating system.

Start off by opening your file explorer, and select a file that you don’t mind deleting.  Right click it and select “Delete” or tap the “Delete” key on your keyboard.  Your computer will probably, depending on your settings, show you a prompt that asks if you really want to delete the file.  Allow it to delete the file, and it should disappear.  However, the file is not really removed from your computer.  Go to your desktop and open up your “Recycle Bin”.  The file you just removed should be sitting in there.  If you changed your mind and don’t want to delete the file, you can restore the file from here.

If you tap “Restore all Items”, all the files in the bin return to their original locations.  If you only want to restore a few things, select them and the click “Restore the selected items”.

As you can see, anything in the recycling bin can be restored with a few clicks.  However, you may want to actually get rid of some files, particularly if you are trying to free space on your hard drive.  In order to do that you need to empty the recycle bin.  The easiest way to do this is to simply use the button.  Once this is done, all the files that are in the recycling bin are, to some level, actually removed from your computer.  It may be possible to retrieve them using backups or system restore techniques, but this is one of the most commonly used ways to clear files.

One last note, some automated tools empty your recycle bin for you.  For example, I use a free tool called CCleaner, which in addition to several other tasks empties my recycling bin.