Please i would like to know the difference this three i get confused a lot. thanks

Taking this your post as an example:
the full url is https://www.nairaland.com/3268365/what-difference-between-url-uri

Analysis:
URL - https://www.nairaland.com/3268365/what-difference-between-url-uri
URI - 3268365/what-difference-between-url-uri
SLUG - what-difference-between-url-uri

Err, something like that. . . . . .
URL: The full url of the resource starting http://, https:// or something like that
URI: Usually the short aspect, more like relative URL (NOTE: this is what you find in many CMSes, in reality URL and URI as like the same)
SLUG: usually short form of a slogan e.g. a uniqueID or whatever

Note: these are not standard definitions, but it is what you will often find in CMSes.

Signed: Master Troll

dhtml18:
Taking this your post as an example:
the full url is https://www.nairaland.com/3268365/what-difference-between-url-uri
Analysis:
URL - https://www.nairaland.com/3268365/what-difference-between-url-uri
URI - 3268365/what-difference-between-url-uri
SLUG - what-difference-between-url-uri
Err, something like that. . . . . .
URL: The full url of the resource starting http://, https:// or something like that
URI: Usually the short aspect, more like relative URL (NOTE: this is what you find in many CMSes, in reality URL and URI as like the same)
SLUG: usually short form of a slogan e.g. a uniqueID or whatever
Note: these are not standard definitions, but it is what you will often find in CMSes.
Signed: Master Troll

^^^^ The ORACLE has spoken, therefore I cannot SPARK!!!!!!!!!!!!

talk2hb1:

^^^^ The ORACLE has spoken, therefore I cannot SPARK!!!!!!!!!!!!

Say what? I am only a TROLL, and an OBSOLETE TROLL at that!

dhtml18:

Say what? I am only a TROLL, and an OBSOLETE TROLL at that!

Thank God you know...

hardebayho:


Thank God you know...

So says a troll-in-the-making.

dhtml18:

So says a troll-in-the-making.

Na wa ooo... You dey look my future ni?

May I? As the answer is quite not the answer...

URI means Uniform Resource Identifier.
URL means Uniform Resource Locator.

and a term which the op never mentioned about but related...

URN means Uniform Resource Name

Now...
An Identifier (or say URI) can be a Locator or a Name.

If we are to relate this in English terms, that's very true...
As an illustration, I can identify the op by Name or by Location of where he lives.

In technical terms, I will use the same examples used before

Here is a URL....
https://www.nairaland.com/3268365/what-difference-between-url-uri#48179571

and here is a URN
www.nairaland.com/3268365/what-difference-between-url-uri#48179571

And either of them can generally be called URI.

Notice the difference between the two of them?
yeah! it's HTTP which is simply a transfer protocol which takes its action on the Transport Layer of the OSI Model. Hence if something is responsible for transportation, then it helps to locate something which in our own case now, a name...

If you ask, what is the name, it is simply the file + the path. that is...

www.nairaland.com/3268365/what-difference-between-url-uri#48179571

Which simply illustrate that there is an html file titled 'what-difference-between-url-uri#48179571' in a folder '3268365' which is in a root folder 'www.nairaland.com' ...

Now, if you notice, I haven't mentioned about slug at all, that is because it isn't part of the specification used to build the www.

..
..
..

I hope I clarified this enough! If you need some reference, your final destination should be at w3.org

I wrote something about this on my blog NoT quite long. But it's from the perspective of the common misconceptions about URI.

tag: 2awesome, dhtml18

^^^You are right, but you have failed to answer the OPs question. In primary and secondary school, and even in JAMB, there is something called: answering a question according to the content. For example:
If a passage says something like that:
Today was a bright any rainy day, dhtml18 in his usual trollin' manner stole seun osewa's password and accessed the administrator's panel to ban toheebDOTcom.

Questions:
1. Who is dhtml18
a. A programmer (wrong, the context did not mention programmer)
b. A thief (correct, because he stole something in the context)

2. Who is seun osewa
a. Owner of nairaland (wrong, the context did not say so)
b. Administrator of nairaland (yes, that is what the context implies)

So, as far as I am concerned, you are speaking generally but not according to the context of the OP.

The places i have seen terms such as slug, uri and url used together is inside CMSes and Frameworks like drupal, wordpress, codigniter, cakephp etc and my initial response was based on these CONTEXTS.

You know, that's why I probably got a D in English for my waec! Thank God for Neco back then...

dhtml18, have you watched arrows? I will like to borrow some of his sentences...

You'r someone else,
You'r something else,
You'r the funny troll master!

Yeah, watched arrows, and yes you are correct that I am a troll. . . .