title: modelBuilder.Configurations.Add and modelBuilder.Entity on OnModelCreating
body: <p>I have just started working on entity framework code first approach, I have written two approaches below and both are working fine.</p>
  
  <p>Please let me know what are the core concepts behind both these approaches and what should follow?</p>
  
  <p><strong>Approach 1 :</strong> <em>Using EntityTypeConfiguration</em></p>
  
  <pre><code>public class BlogsMap : EntityTypeConfiguration&lt;Blog&gt;
      {
          public BlogsMap(string schema)
          {
              ToTable("BLOG");
              HasKey(t =&gt; t.BlogId);
              Property(t =&gt; t.BlogId).HasColumnName("BLOGID");
              Property(t =&gt; t.Name).HasColumnName("NAME");
              Property(t =&gt; t.Url).HasColumnName("URL");
          }
  
      }
  
  
  public class BlogContext : DbContext
      {
          public BlogContext(string name)
              : base(name)
          {
          }
  
          public IDbSet&lt;Blog&gt; BLOG { get; set; }
  
          protected override void OnModelCreating(DbModelBuilder modelBuilder)
          {
             modelBuilder.Configurations.Add(new BlogMap(string.Empty));
          }
      }
  </code></pre>
  
  <p><strong>Approach 2 :</strong> </p>
  
  <pre><code>public class Blog
      {
          public int BlogId { get; set; }
          public string Name { get; set; }
          public string Url { get; set; }
          public virtual List&lt;Post&gt; Posts { get; set; }
      }
  
  
      public class BloggingContext : DbContext
      {     
  
          public DbSet&lt;Blog&gt; Blogs { get; set; }
  
          protected override void OnModelCreating(DbModelBuilder modelBuilder)
          {
              modelBuilder.Entity&lt;Blog&gt;();
  
          }
      }
  </code></pre>
  
  <p>Please provide me concept/blogs on entity,since i have just started.</p>