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- Let's talk about software managers.

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Now, what are software managers?

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Software managers are the solution

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to the dependency problem,

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and they're really cool.

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Software managers fix
the dependency problem

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by working with the repositories.

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A repository is an online resource

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where packages are stored.

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And the nice thing about
a repository is that

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as long as you make sure that all packages

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that may ever be required

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as a dependency are available,

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the software manager is taking care

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of the rest.

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Before installing a package,

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the software manager
analyzes the dependencies

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and it'll try to fetch the dependencies

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from the repositories.

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So you will never see

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the missing dependencies messages anymore.

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Now, software repositories are provided

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by the Linux distributions.

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Typically, when you install
a Linux distribution,

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you get access to the
standard software repositories

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and every distribution makes
sure that you have access

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to thousands of packages in
the software repositories.

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Alternatively, you can work

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with software repositories
that are provided

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by software vendors

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and you can even create your own.

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Software managers that are common,

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in the Reddit and family,

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we use YUM and DNF.

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In Ubuntu, it's APT,

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and we will explore what they
look like in the next video.

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But first, I want to make
a drawing to show you

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how software managers
relate to the repositories.

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In order to understand software managers,

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you should understand the dependencies

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because it's all about
dealing with dependencies.

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So in a software manager,

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the central point is the repository.

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Now what is the repository?

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Well, the repository is an
online and onsite resource

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that contains packages.

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Many packages.

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You can have one repository,
that sounds really common.

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Most of the cases, you will
have multiple repositories.

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And then you are going to
use your software manager

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to install packages
from these repositories.

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So let's imagine that DNF
is your software manager.

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Then DNF is going to be
configured to fetch the packages

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from these repositories.

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And if it finds any dependencies,

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it'll automatically
resolve these dependencies.

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And the result of the work
of the software manager

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is that it keeps track
of installed packages

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in a local database.

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And having this local
database is a good thing,

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because if you have this local database,

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then you can see which
version, for instance,

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of a software package you are using.

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Now, why is that good?

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Well, that is good

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because your software
manager can fetch an index

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from the repository.

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In this index, it can compare the index.

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It can compare the versions

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of the packages in the
software repository,

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to the versions

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of the packages that you
have installed locally.

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And then you can even do update accents to

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make it easy to update packages.

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And all of these are benefits
of software managers.

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I have used DNF in my example,

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of course, this works

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for other software managers,
such as APT and YUM as well.