install not only copies files but also changes its ownership and permissions and optionally removes debugging symbols from executables. It combines cp with chown, chmod and strip. It's a convenient higher-level tool to that accomplishes a common sequence of elementary tasks.

An advantage of install over cp for installing executables is that if the target already exists, it removes the target file and creates a new one. This gets rid of any current properties such as access control lists and capabilities, which can be seen both as an upside and as a downside. When updating executables, if there are running instances of this executable, they keep running unaffected. In contrast, cp updates the file in place if there is one. On most Unix variants, this fails with the error EBUSY¹ if the target is a running executable; on some it can cause the target to crash because it loads code sections dynamically and modifying the file causes nonsensical code to be loaded.

install is a BSD command (added in 4.2BSD, i.e. in the early 1980s). It has not been adopted by POSIX.

¹ “Text file busy”. In this context, “text file” means “binary executable file”, for obscure historical reasons.

Witha tar.gz generally just decompress it to the folder you want it installed in such as /usr/bin or /usr/sbin, etc… However, in this case it looks like the linux version of putty is already in a repository so you should not be using a targz you would be better serves using the package manager in Debian apt. Using apt-get install, see for putty from repositories. How to Install PuTTY on Ubuntu Linux | Numato Lab Help Center

Use dpkg - package manager for Debian.

dpkg -i yourpackage.deb to install a package.

You can install applications different ways. Terminal, the Ubuntu Software Center, and Synaptic.

With the Ubuntu Software Center, you just open it from the Launcher, and search for the application that you want.

If you know the right commands to install via terminal, then you'd just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, you can run the command(s) needed to install the application.

For synaptic, it has to be installed on you system. To install it, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt install synaptic

Once installed, you can open it, and search for the application that you want to install, and just mark it for installation.

Also in some cases, you have to download either a .deb file in case of your question about Chrome, and have to manually install it, or a .tar.gz file, and that also have to done manually.

Now as far as Chrome is concerned, you can install it by downloading the .deb file, or just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

For 32bit

wget https://dl.google.com/linux/direct/google-chrome-stable_current_i386.deb
sudo dpkg -i google-chrome-stable_current_i386.deb

For 64bit

wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
sudo dpkg -i google-chrome-stable_current_amd64.deb

If you encounter any error during the installation, when its done do

sudo apt -f install

For pros and cons of the different ways to install see this Post.

^{Source for Chrome installation: Google}

Addition

Installing software in Ubuntu can be done several ways:

Ubuntu Software Center

You can search for an application, or go through the categories:

Synaptic Package Manager

You can search for an application, or go through the categories:

Installing via Terminal

Installing from terminal can be done in several ways:

APT
You can search for an application. The command to search for software is:

apt search <application_name>

Adding Repositories:

Edit the sources list file, and add

sudo -H gedit /etc/apt/sources.list

Or add from terminal

sudo add-apt-repository <repository_name>
sudo apt update
sudo apt install <application_name>

Others ways you can install

Manual download of a .deb (Debian package):

• Once downloaded, you can double-click on the package to have it open in the Software Center, from where you can install it.

• Or, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, navigate to the download location, and run the command(s) below:

  sudo dpkg -i <package_name>.deb
  

Other options:

• .rpm files are packaged for Fedora or Mandriva, but you can use alien (you can install using Synaptic) that allows you to convert .rpm files to .deb. (may not work all the time)

• .tar.gz files are compressed. If you see the .tar.gz, it could be compressed files that have a pre-compiled binary file, or files that have the source code allowing you to compile the application from source. To find out how to install from a .tar.gz, see How to install from a .tar.gz.

For more info see Installing Software, or A beginners guide to installing programs in Ubuntu

Generally when you install a program, you will be able to run it from the command line by typing the name of the program installed. Note that this name will not always match the name of the package (e.g. alsa-tools provides as10k1, hda-verb, sbiload and us428control).

As discussed in the comments by George and Terrance, the program must also be in your PATH variable so that you don't require the full path to run it. For some reason "cowsay" is not, so you can temporarily add it as described by Terrance using:

PATH=$PATH:/usr/games

If this works, you can permanently add this location to your path variable. This can be done by modifying .profile, .pam_environment, or other locations as described in the references below. For example, adding the following to ~/.profile should work:

export PATH="$PATH:/usr/games"

The above will take effect on the next login.

References:

• How to add a directory to the PATH?
• https://help.ubuntu.com/community/EnvironmentVariables#Persistent_environment_variables

In the terminal I chose directory and did: "sudo apt-get intall *.deb"

Here there are two problems:

1. intall is misspelled, it should be install
2. apt-get will install local packages if a path is provided in the way of ./package.deb or /path/to/package.deb

This should achieve the desired result

sudo apt-get install ./*.deb

This will install the packages and any dependency needed if it can find them.