1. Manual Installation
To install Tiki, you basically point your browser to tiki-install.php and follow the instructions. For the vast majority of setups, this works nicely. But what if it doesn't work out for you? (special server setup, etc). Don't worry, there is an alternate way to install Tiki. This assumes you use mysql and have access to phpMyAdmin and know how to use it. Essentially, tiki-install.php does two essential things. It creates your database connection file (db/local.php) and populates the database with tables & data needed by Tiki.
1.1. Create your db/local.php file

<?php $db_tiki='mysql'; $dbversion_tiki='8.0'; $host_tiki='localhost'; $user_tiki='my_database_username'; $pass_tiki='my_database_secret_password'; $dbs_tiki='tiki_80'; $client_charset='utf8mb4';
1.2. Insert tiki.sql
use the encoding as described on Understanding encoding
1.3. Insert secdb (optional)
1.4. Rename _htaccess for clean URLs (optional)
You can rename _htaccess to .htaccess
See Apache Clean URLs
MultiTiki
The instructions above assume you are installing one Tiki. If you are using MultiTiki, please see MultiTiki Manual Installation